Hello dear readers. Alexander is with you again, and in today's article I will talk about a computer fan, which plays a very important role in the construction of computer cooling systems.

One of the important components of uninterrupted, reliable and long-term operation of your computer is a high-quality and highly efficient cooling system for all its components and assemblies.

It doesn't matter if it's a laptop or a powerful gaming computer. High-quality heat removal from heating components significantly extends their operating time, and is important for any device.

At this stage of technology development, the main way to cool hot computer devices is air cooling using specially designed fans.

Their size, rotation speed, performance, manufacturing technology, and even the shape of the impeller of the blades, all this greatly affects the quality of cooling of the entire computer system as a whole.

A fan connected to a radiator (it can have a different shape, size, material and manufacturing process, include components that help to more quickly and efficiently remove heat from a heating element, for example, heat pipes). This whole sandwich is called a cooler.

Since the number of computer fans in powerful system units can reach a dozen or more, many users have the question of how they can be replaced or repaired when annoying noise occurs or the fan fails. If you did not notice the failure of the fan in time, then this can lead to the loss of expensive equipment due to its overheating.

This question is relevant especially during the summer period, when the average temperature in a house or office rises compared to the winter period, and since computer fans take air from the environment, it naturally rises inside the computer system.

It is very easy to buy and replace a case fan, and every user with at least some skills in handling a screwdriver can do it.

In most cases, it is impossible to replace a processor fan or a fan on a video card, due to their non-standard sizes and mounting methods, which leads to the need to completely replace the cooling system of this unit.

To select and further purchase a high-quality case fan, cooler for a processor or video card, you must have information about the main types, characteristics of fans and their design. It will also help you (if required) to independently remove, disassemble and lubricate the annoyingly noisy fan.

After reading this article, you will know very well how fans of different price categories differ from each other, learn to understand their technical characteristics, and you will be able to make the right choice in favor of a particular fan model for a computer when buying it.

So let's get started ...

Computer fan assembly

A computer fan has three main parts:

• Frame

• Impeller

• Electric motor

The fan casing is shaped like a frame and serves as a base for mounting an electric drive (electric motor) and impeller blades. Depending on the manufacturer and the quality of the product, the body can be made of plastic, metal or rubber.

The impeller is a set of blades located in a circle on the same axis with the electric motor, at a certain angle and fixed to the fan casing using bearings of various types. During rotation, the impeller blades capture air and, passing it through them, create a constant directional air flow that cools the heating element.

In the manufacture of computer fans, DC motors are used, which are rigidly attached to the fan case.

To cool a computer, computer components and devices, two types of fans are currently used:

• Axial (axial) fan

• Centrifugal (radial) fan

They differ in principle of operation and design.

The axial fan is widely used in the design of cooling systems for various computer equipment due to its ease of manufacture and versatility.

An axial computer fan is used to cool the system units of computers, laptops, very hot electronics on motherboards, central processors, video cards, power supplies and other equipment.

The main way of using axial fans is to blow cooling radiators installed on electronic devices that require forced heat removal.

A centrifugal (radial) fan is a rotating rotor made up of spiral blades. In this type of fan, the air is drawn in by the rotating rotor through the side opening, inside the casing, where, due to centrifugal force, it is directed to the heated radiator, passing through the fins of which, it picks up the heat emanating from them and removes it outside.

The radial fan is mainly used only for cooling laptops, powerful video cards and as additional cooling for powerful computers and low-profile servers (blover).

The advantage of centrifugal fans, over axial fans, is the possibility of direct outlet of heated air outside the computer system unit and greater reliability (due to their design features).

Disassembling and lubricating a computer fan

We may need to disassemble the fan for the computer to lubricate it, or to clean it from dust.

The main dust collectors are the fan blades, and due to the high rotation speed, small dust particles densely settle on the surface of the blades, and they can only be cleaned qualitatively by hand using any damp cloth or other similar improvised material. A vacuum cleaner or compressed air will not help here.

We will disassemble an old axial fan on a slide bearing of the ADDA company (this company produces very high quality fans, but we did not come across them on sale).

The first step is to carefully remove the sticker with the manufacturer's logo, preferably without damaging the adhesive base. She will still be useful to us.

Next, we take out the rubber or plastic plug that protects the bearings from the penetration of foreign particles into them (in fans using sleeve bearings, it also serves to prevent grease from leaking out).

Well, the last and most difficult thing is to remove the fixing plastic washer from the impeller shaft.

It looks like this:

The retaining (circlip) ring has a cut in one place and a rigid structure (it bounces very easily), so when removing it, be very careful so that it does not fly off anywhere. It will be difficult to find a thin and small ring (tested in practice), and a fan without a retaining ring is inoperative. To remove it, it is better to use thin tweezers or any other object that will be convenient to pick up and hold it.

After removing the retaining ring, the process of disassembling the computer fan is completed. We take out the impeller and proceed to cleaning and lubrication.

Fans assembled on a sleeve bearing must be lubricated with thick lubricants, since it is necessary that the lubricant is constantly on the metal axis of the fan during its operation. It is enough to slightly lubricate the axle of the fan impeller itself, and after installing it in the frame with the electric motor, add a small amount of lubricant (up to the level of installation of the retaining ring) from the back of the computer fan. This is done so that while the fan is running, the grease liquefied from heating flows through the metal sleeve to the bearing and lubricates the space between them.

Fans for computers assembled on rolling bearings (ball bearings) are lubricated with liquid materials. Silicone oil PMS-100, PMS-200, which can be purchased at radio parts stores, is excellent for these purposes. Lubrication of such fans is complicated by the fact that the bearings are small and the clearances between the bearing housing and the balls themselves are very small. I personally lubricate them this way. I take out the bearings from the fan. I wipe them well with alcohol (or something degreasing). I wipe them dry and for 15-20 minutes (while I clean and lubricate the fan itself) I throw them into a container with silicone oil. Then I take them out with tweezers, put them on the impeller shaft and assemble the fan. The assembly is carried out upside-down.

Computer fan specifications

The fans are characterized by the following main technical parameters:

• Rotation speed (rpm)

• Created Airflow (CFM)

• Generated noise level (dB)

Rotation frequency

How many revolutions around its axis can a fan impeller make in one minute.

Air flow

Fan capacity is expressed in terms of the amount of air flow generated and is expressed in Cubic Feet Per Minute (CFM), which is how much air the fan can pass through at a certain speed per minute. It is the air flow created by the fan that affects how much of the dissipated heat can be removed from the heating element in a certain unit of time.

The more CFM, the more efficient the fan. In this case, it is worth paying attention to the level of noise it creates. In many cases, a less efficient but quieter option may be preferable.

To increase the airflow, it is better to use large fans with low rotational speed than small ones with higher rotational speed. This will save you unnecessary noise.

Noise generated

Calculated in decibels. This characteristic is influenced by where and how the fan is installed, in what conditions it works, the type of bearings installed, the workmanship, the rotational speed and the size of the fan. Read more at the end of the article.

Types of bearings used in computer fans

One of the most important parameters that you should pay attention to when choosing a fan for a computer is the type of bearings used in it.

There are several types of bearings that computer fans are based on. They influence such important parameters for us as reliability, MTBF and fan noise.

The following types of bearings are by far the most common in the manufacture of computer fans.

There are rarer and more expensive bearing options, which I will discuss below.

• Sleeve bearing

• Ball bearing

The plain bearing is very easy to manufacture, and therefore the cheapest of all types of bearings. To give stability to the impeller, during its rotation, a metal or (in more advanced versions, ceramic) cylinder is used, with a hole in the middle. It is into this hole that the steel axle is inserted, to which the impeller is attached.

Due to such a simple and cheap technical solution, all the disadvantages of this type of bearings follow.

When the fan is just purchased and installed, it will delight you with silence during its operation, but as soon as the lubricant begins to dry (and this happens in about a year, depending on the operating conditions), it will start making an unpleasant noise.

It arises from the resistance that appears when the impeller axis frictions against dry and contaminated grease inside the bearing.

Further long-term operation of the fan without lubrication will lead to the appearance of even greater noise, the beginning of abrasion of the bearing itself, and, ultimately, will lead to the complete impossibility of restoring the fan's performance, which will require its replacement.

The performance of the sleeve bearing is highly dependent on the ambient temperature, the faster the grease will dry out, and the more often you will have to clean and lubricate the fan yourself, or change it to a new one.

Also, one of the disadvantages of fans with sleeve bearings is their low efficiency when working in a horizontal position.

With this arrangement of the fan, the grease inside the bearing flows down to one side, which leads to its uneven distribution and faster failure of the fan.

From all that has been said, we can conclude that fans with sleeve bearings, especially high-quality models, can be effectively used in cooling computers that do not require strong heat dissipation and whose operating time does not exceed 8-10 hours a day (office or home low-power computers) ...

For all their shortcomings, such fans are the least expensive, and if you follow them, lubricate and clean them from dust at the right time, then they can work for a long time without disturbing you with unnecessary noise.

Now let's move on to higher quality and more expensive fan models built on the basis of two ball bearings.

A ball bearing is a metal housing in the form of a ring and an inner sleeve with balls enclosed between them. The rolling bearing is non-separable, so the grease inside it does not leak out and does not become contaminated. This significantly extends the life of the fan, and its performance deteriorates very slightly, during the entire period of operation.

Likewise, a rolling bearing is less susceptible to high temperatures than a plain bearing, and is suitable for cooling computers with strong heat generation.

Two ball bearings on the fan hub with a retaining ring

The level of acoustic noise emitted by modern fans equipped with ball bearings is not louder than that of new sliding bearing fans, and during the entire period of use it practically does not change, unlike the competitor.

You will rather hear frictional noise of air entering or exiting at high speed against the ventilation openings of your chassis than the noise of rolling bearings.

A fan on rolling bearings allows you to create on its basis much more thoughtful and effective options for cooling computer systems due to the ability to place them in any convenient position without fear of deteriorating the fan's performance or shortening its life.

Since a rolling bearing is technologically more complicated to manufacture than a sleeve bearing, it is accordingly more expensive and products based on it have a high price. And if we consider that a high-quality fan has two rolling bearings, then the price rises even more.

At the moment, the choice of a roller bearing fan seems to me the best option. There are many manufacturers, the quality of the products is high, and the prices, due to the high competition, are at an acceptable level. It is recommended to install on all existing computers.

Purchasing these fans will save you from many problems associated with their maintenance, since their MTBF is approximately the life cycle of a modern computer, and you will change ball bearing fans along with all the contents of your computer :).

Various types of bearings can be used to produce one fan. For example, a fairly common option is a fan with one sleeve bearing and one rolling bearing. This solution does not eliminate the existing drawbacks of fans, but allows manufacturers to save money and occupy the price niche they need, between expensive and cheap fan models, and you and I can get a good product at an affordable price.

Ceramic Bearings

A rolling bearing, in the production of which ceramic materials are used. The performance properties of ceramics for bearing production are superior to those of metal. The declared service life is twice as long as conventional bearings.

Ceramic roller bearings allow fans built on their basis to be used at temperatures in which other types of bearings are unable to work for a long time.

These are the most durable bearings used in fans today, but also the most expensive.

Fluid Dynamic Bearings

A technologically advanced sleeve bearing, in which the rotation of the impeller shaft occurs in a layer of special grease, which is constantly inside the bushing, due to the pressure difference created during operation.

The noise level of a fluid dynamic bearing is considered to be the lowest.

The MTBF is almost twice as high as in plain bearings, but lower than in rolling bearings. Fans with this type of bearing are expensive and very rare due to the complexity of their manufacture. Produced by a small group of manufacturers only.

Rifle bearing

Sleeve bearing with special grooves on the inner side of the bushing and along the impeller mounting axis, along which the lubricant is uniformly distributed. The noise level and operating time are roughly equivalent to those of a hydrodynamic bearing.

Computer fan dimensions

Since the electronics of computer systems that need cooling have different sizes, fans of different capacities and sizes are required to cool it.

All computer fans that you can buy come in standard sizes. When choosing computer components (especially cases), you should pay attention to this. In devices with non-standard fans, it is very difficult, or even impossible, to replace a failed fan, which will lead to the need to replace the entire cooling system.

Not so long ago, the cooling systems of some video cards suffered greatly due to the installation of low-quality fans, which failed before the video card became obsolete. Personally, I replaced coolers and fans, only for my computer, on two video cards (NVIDIA Geforce 4 Ti 4200 and ATI Radeon X800XT).

This used to be a big problem, but now cooling system manufacturers have solved it by introducing centrifugal fans and much better quality axial fans.

Standard dimensions of axial computer fans (in mm)

40X40, 60X60, 70X70, 80X80, 92X92, 120X120

The frame thickness of 80, 90 and 120mm fans is 25mm, although there are fans with 15, 30 or 35mm frames. The frames for the smaller fans are 10, 15 mm.

Below in the image you can view both the overall and installation dimensions of the main standard sizes of computer fans (sorry for the small captions, for a more detailed view, click on the image).

Custom sizes of computer fans 140mm, 95mm

140mm fans have recently appeared due to the increased power requirements for cooling systems of modern computers.

Initially, in their bulk, they were used to cool computer power supplies and coolers for cooling processors, but now the situation has changed.

Many wind turbine manufacturers have started making 140mm fans for retail sale.

Manufacturers of computer cases are also not lagging behind in equipping their offspring with seats for new items.

It is worth paying attention to the fact that some brands, such as Noctua, Evercool and the like, 140 mm fans can be installed in 120 mm slots, using additional mounts or specially designed forms of the fan case.

The price of a 140mm fan is slightly higher than that of its smaller counterparts, but for a little more money and a slight increase in size, you get more airflow per unit. time, a decrease in fan speed, and as a result, an improvement in the cooling of the system unit and a decrease in noise from it.

We can conclude that over time, 140 mm fans will displace 120 mm, as it was not so long ago with 92 mm, and will become the standard.

Connecting computer fans

All computer fans, connected to the motherboard or power supply, operate from 12 volts in standard mode.

Fans can be with automatic speed control of the impeller, or without it.

Fan contact types

All computer power supplies have a standard connector (Molex) for supplying electrical power to a variety of devices (hard drives, optical drives, and fans).

To connect to a computer power supply in the fans, both a regular four-pin connector (like Molex) and reduced versions can be used.

To operate the fan, out of four contacts, only two are used (Ground and 12 volts).

This is what one of the most popular in desktop computing looks like - the Molex 4-pin power connector:

It has four contacts:

• yellow wire + 12V
• red wire + 5V
• black ground wires

A fan connected to it with a standard pinout on the power connector will operate on 12V.

If we need to reduce the fan speed, then we can easily connect it to 5, 6 or 7 Volts.

To do this, we need to swap the wires in the fan power connector.

The contacts at the ends of the wires have a standard structure.

They are fixed with a pair of bending metal tendrils in the plastic part of the connector. To remove the contact from the connector, it is necessary to press these protruding antennae into the inside of the contact and then calmly remove the wire and insert it into the desired place of the connector.

Reduced connectors are used to connect to the connectors on the motherboard or to other devices that have the ability to adjust the fan rotation speed.

They come in two, three or four pins.

The 2-pin connector has two wires and supplies the standard + 12V voltage.

In the 3-pin connector, in addition to "ground" and 12V, there is a wire for communication with the tachometer. The tachometer is designed to regulate the rotation speed of the fan impeller by changing the power supply voltage. This parameter is configured in the motherboard BIOS or special software.

Fans with 4-pin connectors are installed in the cooling systems of processors and video cards. Their speed is automatically controlled using PWM (pulse-width modulation). Depending on the temperature of the element to be cooled.

If there is no load on the central processor or video card, then they then heat up weakly and they do not need strong cooling. In this case, the PWM module reduces the fan speed to the minimum required values.

As the load rises, the processors generate more heat and the PWM will gradually increase the fan speed as the temperature rises to prevent overheating.

Computer fans can be equipped with two different types of connectors connected in parallel. This is usually a standard Molex and a small 3 or 4 pin connector. You can only connect power to one of them.

Adjusting the rotational speed of computer fans in various ways significantly extends their life and reduces the noise they make.

Fan noise and how to deal with it

The noise level generated by a fan during its operation is an important indicator when choosing a particular model.

Acoustic noise is measured in dB (decibels), and must be indicated by the manufacturer in the technical documentation for their products.

Actual data under operating conditions will differ significantly from those declared by the manufacturer. The measurement of noise performance is carried out under ideal conditions, i.e. the fan works in a free position, does not have any obstacles to the passage of air flow through it, and is not attached to anything.

Installing in a computer case or mounting a fan on a radiator will greatly affect the noise it makes, and not for the better.

Now let's look at what factors influence the acoustic noise of the fan.

1. Low-frequency vibrations emanating from the bearing during operation, which are transmitted to the computer case through the fan frame mount.

Control methods:

• use high-quality fans with low noise bearings
• use special (vibration-damping) gaskets and silicone fastening screws
• use of rigid (with thick metal walls) computer cases

2. The shape of the ventilation holes through which the air flow enters or exits.

Here, the noise is generated by the air being sucked in, or escaping outside, which, under pressure and at high speed, passes through the narrow ventilation openings.

Control methods:

3. Shape, quantity, angle of inclination and quality of manufacturing of blades.

The blades directly affect the acoustic performance of the fan. When the air flow passes through them, they cut it, as it were, from which noise of a certain spectrum is created.

The spectrum and noise level for each fan model will be different, and depend on the rotation speed, surface quality, angle and number of blades.

You can influence this parameter only by choosing the correct fan model.

If you can take into account all of the above factors when buying a computer, then you will not have to worry about the noise it makes.

Of course, you won't be able to make your computer perfectly quiet, but it will certainly be better than if you don't use the above tips.

Please, if it's not difficult for you, answer the questions below. It will take a little time, but in order to give the information you need, you need to do it. It is very important for me. Thank you.

Introduction

For PC users or system builders who do everything themselves, the issues of cooling and ambient temperature are always relevant. That is why we are going to start from the very basics with this introduction to the theory of cooling. Every year we have new readers and every year we notice the same questions being asked on our forums. The very last thing we want is for a costly project to fail as a result of the error found in most of the basic principles that keep hardware running at acceptable temperatures.

Since the topic we have covered is quite extensive, and we want to offer you a complete guide, we have divided all the material into two parts.

So, first of all, we will talk about the cases, including the issues of the location of the power supply. We will then review the possible disadvantages of other solutions. Optimized airflow is the most important question in all information about an air-cooled system, so we plan to share this with you in more detail. Then we'll take a look at standard case fans and show you why even a beginner shouldn't be afraid to apply thermal grease to parts. If you also remember that it is important that there is some space between your graphics cards in a multi-GPU configuration, and you understand why the often underestimated fans on the side panels can be useful, then you can better equip your PC so that it can do less to survive the summer heat with losses.

Cooling theory at a glance

Energy saving

We cannot stress enough the idea of ​​what a large-scale undertaking a properly selected cooling system can turn out to be. Computers are among the most inefficient devices of all time because most of the electricity they use is converted into heat (thermal energy). There is no getting away from this, you have to accept it as reality.

Even a regular 40-watt light bulb emits enough heat to melt plastic and start a fire. Computers consume 60 watts or more when idle. Under load, this figure can skyrocket by a factor of ten or more! Remember this fact. It will form the basis of our discussion and will help you understand how difficult this task really is - cooling your PC.

Heat must be dissipated so that the PC components do not exceed the specified maximum temperature. This task is performed in several stages:

• Dissipation from the surface of a component that generates heat (whether that component is a CPU, video card, or motherboard voltage regulator).
• Heat absorption by the contact pad and its transfer to the cooling radiator fins.
• Radiation of heat into the air (which, unfortunately, conducts heat rather poorly).
• Removing hot air from the housing.

In steps 1-3, we used industrial fan heatsinks designed to fit as many interfaces as possible and sometimes raise questions about installation on more complex or specialized platforms. Fortunately, most of these issues can be easily resolved. However, the last stage requires more detailed planning, so we will start with an overview of the airflow information.

Of course, there is a direct link to the location of the components inside your case. And therefore, below we will briefly tell you about the design of power supplies, the direction of rotation of the cooler fan and case fans.

Traction formation:

Hot air goes up, cold air goes down. This is why the top of the case is usually the hottest. We must keep this basic physics principle in mind at all times when planning a cooling system.

Test system configuration

Basic idea and test configuration

In order to compare the results as comprehensively as possible, and under equal conditions, we used an outdated test platform, with which we fairly accurately simulated three heat dissipation options - 89, 125 and 140 watts. In the first version, the processor frequency was reduced to 2.2 GHz, in the second version it worked at the standard frequency, in the third version it was overclocked to 3.0 GHz.

Test bench configuration
CPU	AMD Athlon 64 FX-62 (Windsor) 2.8 GHz, Dual-Core, 2 x 1 MB L2 Cache, Socket AM2, 125 W TDP
Motherboard	MSI K9A2 Platinum, 790FX chipset, Socket AM2 / AM2 +
RAM	2 x 2 GB DDR2-800
Cooler 1	Original boxed AMD cooler for Athlon 64 FX-62
Cooler 2	Xigmatek Aegir High Performance Tower Cooler with 120mm Fan

Using the Xigmatek Aegir cooler, we tested hardware with different power levels and cooling results for each build option. This cooler is powerful enough to evenly cool a 140W old FX processor under heavy load. Although the device seems more solid than the noisy "boxed" cooler provided by AMD, most users need such a purchase in order to get a worthwhile thing once and for all. We took our measurements in a room where the temperature was kept constant at 22 ° C.

Cooler Xigmatek Aegir
Dimensions (general), (LxHxW)	130 x 95 x 159 mm
Weight	670 g without fan
Material	Copper / Aluminum
Heat pipes	Six in total (2 x 8mm, 4 x 6mm)
Technology	Dual-Layer Heatpipe-Direct-Touch (D.L.H.D.T.) structure, Four heatpipes with direct CPU contact
Fan	120 x 120 x 25 mm
Bearing	Long Life Plain Bearing
Speed ​​range	1 100-2 200 rpm.
Air flow	Max. 150 m³ / hour
Noise level	Max. 20 dB (A)
Color	Transparent black, 4 white LEDs
Connection	4-pin PWM connector
Connector compatibility	Socket 764/939/940 / AM2 / AM3, LGA 775/1156/1366

We did most of our testing with this high performance cooling unit because tower coolers are currently the most popular cooler models. Also in our review there is an additional chapter on coolers with downward airflow (so-called "boxed" coolers).

Power supply: installation location and case selection

The power supply is located at the bottom of the case

In many modern PC cases, the power supply is located underneath the motherboard. This installation option has many advantages, so we highly recommend a chassis with this configuration. In the picture, you can see that the fan draws in cool air from the "floor" through its own inlet, uses this air to cool active components inside the power supply, and expels it at the back of the device.

Advantages of installing the PSU at the bottom of the case:

• Uniform supply of cool air from the "floor" to the inside of the case.
• Direct removal of air from the power supply case.
• Lower fan speed.
• Cooling allows you to achieve greater power supply performance.
• Less thermal stress on components, longer service life.
• The center of gravity of the body is located below.
• The power cable does not hang down and does not interfere with the connection of other external devices.

Flaws:

• The body must have sufficiently high feet.
• A dust filter must also be available.
• The formation of extraneous noise is possible, depending on what material the floor is made of.

Despite some minor drawbacks, the above configuration is preferred over some of the other build options that we'll also cover, and you should always pay attention to the case that houses the PSU. But you can also make a mistake here.

Do not install the power supply so that its air intake hole protrudes into the computer case. Thus, you can install a power supply unit only if you are dealing with "quiet" power supply units with passive cooling so that warm air rises upward. Otherwise, you will be faced with the forces acting during convection and, possibly, this will lead to a situation in which a screw or any other poorly fixed part can fall into the power supply.

The power supply is located at the top of the case

Older ATX-spec PC cases have the PSU located right under the top cover of the case. Air is sucked into the PSU from inside the computer, and then thrown outside the case. This presumably improves dissipation and prevents heat build-up. However, this also causes the power supply to absorb a large amount of waste heat from the graphics card and processor. As a consequence, you get underperformance from the PSU, which makes it nearly impossible to achieve maximum energy and performance at temperatures in excess of 40 ° C (since they are usually based on operating conditions around 25 ° C). The lifespan of the components inside the PSU also suffers.

Advantages of top mounting:

• Promotes better cooling in some systems.
• A shorter cable is required for the 12V line.

Flaws:

• Higher PSU temperatures.
• Inefficient and noisy work.
• The system wears out faster.

Perfect body ...

It does not exist. However, large, well-engineered "tower" cases such as those found on the Corsair Graphite 600T came close to being ideal. Inside this case, the air flow does not encounter obstacles in its path. The capacity, rear cable routing, and numerous fans and air filters are all features of this model, making it a near-perfect solution.

Whenever possible, you should pay as much attention as possible to enclosures in which the air flow moves up and down unhindered. If you want to include an especially long graphics card in your configuration, you will need a case as deep as possible. Otherwise, the card will obstruct the airflow. Thick cables should always go to the back. Also, anything that dangles inside the case will significantly reduce the speed of the air flow.

Airflow: face up tower coolers

Possible mounting options for tower coolers

Tower coolers are preferred over a combination of heatsinks and fans that blow air into the processors. However, it is very important that you pay attention to the correct orientation of the PSU during installation.

Since there are many bugs to be faced at this stage, we will look at the different build options before summarizing the most important rules.

Tower cooler mounting in vertical position

Most often, vertical arrangement is used in assemblies based on Intel components. Machines with motherboards based on Socket AM2 + or AM3 need a cooler with a special mounting system that allows the PSU to be installed at a 90 ° angle.

Of course, tower coolers can be installed in cases in which the power supply unit is mounted on top. In such cases, the schematic drawing will look like this:

It should be noted that the rear wall of the case must be either perforated or there must be a fan on it. It will be even better if there is an exhaust fan in this place, which, in most cases, can replace the second fan installed on the processor heatsink. Of course, this scenario can be improved as well.

Even with a top-mounted PSU, the airflow can be adjusted for the better by introducing additional cool air from the bottom of the case into the cooling process.

Airflow: horizontal tower cooler

Installation of a tower cooler in a horizontal position

Let's return to Socket AM3 from AMD and consider the option of mounting the cooler in a horizontal position. What at first seemed like a disadvantage to us can, in fact, turn into a valuable quality. Remember cravings? If warm air rises upward, why not take advantage of this? To mount the component horizontally, you need a case with ventilation from the top.

We also used an additional exhaust fan on the side, since many tower coolers move some of the air to nearby components (voltage regulators, for example), and this part of the "scattered" air must also be removed. Horizontal mounting is also possible when using the power supply, which is mounted inside the case at the top.

However, in such a scenario, the shortcomings of the power supply unit, which is mounted in the case at the top, become really noticeable, so we definitely do not advise you to move all the heated air from the processor to the power supply unit. Indeed, there are many better solutions.

If you do decide to do this, make sure your assembly has at least an exhaust fan in the back of the case.

Bottom ventilation helps create additional cooling airflow.

Airflow: Common Installation Errors

Possible installation options and layout planning errors

This seems like a fairly straightforward layout, but given that there are so many different types of processor sockets and unique cooler configurations, it is fairly easy to unknowingly make mistakes that negatively impact the performance of a cooler.

In our first example, the cooler is installed horizontally. However, without ventilation at the top, heat builds up and travels back to the processor.

In this scenario, the case is distinguished by the presence of ventilation from the top, but it lacks additional ventilation from the side. Air has to be bypassed and ends up accumulating behind the cooler.

We recently saw this example: cool air moves in spite of the effects of convection (as well as exhaust fans running to no avail). Unfortunately, this is an example of total failure.

Airflow: from unique systems to conventional coolers

Downward Airflow Coolers (Best Budget)

The boxed heatsink and fan kits you get from AMD and Intel are not efficient enough because the airflow generated by these components is not aligned with the vents in the case. This is why they move air directly to the motherboard. At best, you can hope that the powerful logic circuits of the motherboard will receive at least some cooling. But it is still a question whether this is compensated by the limited performance and higher noise levels. We noticed that this is more of a case for boxed coolers from AMD, which can barely keep up with supplying enough air to keep 125W CPUs running smoothly and often have fans spinning up to 6,000 RPM, which leads to annoying high noise levels.

For other cooling configurations, the rest of the components, chassis and built-in fans play an important role in the operation of coolers with downward airflow.

The computer shown in the picture above is receiving insufficient airflow. This PC has no ventilation at the back, and the graphics card further inhibits convection.

That's better! This configuration allows even a regular retail boxed cooler to dissipate heat efficiently.

Build options:

Optimization with side ventilation

Having an often overlooked side fan actually seems logical if you are using a cooler with downward airflow, as the cool air passing through the vents goes straight to the CPU cooler. The rest of the components can also benefit from these holes, so the latter may indeed be needed.

You can either choose a case with a large, slow and quiet fan, like the LC-Power Titus ...

Or prefer a cooler with a couple of 120mm fans, such as the one inside the Enermax Hoplite case.

Airflow: HDD cooling

Front Ventilation & HDD Cooling

This is the most common arrangement of components. Air is drawn in from the front of the chassis and immediately used to cool installed hard drives. This configuration is sufficient for cooling, problems can only arise if all the bays in your chassis are occupied.

Since, in the interest of protecting data and extending the life of the drive, you should avoid heating the hard drive above 30 ° C, we decided to look at a couple of practical examples.

Before us is a classic configuration: a hard drive in a 3.5 "bay, located behind a 120-mm front fan.

Here is a front-mounted hot-plug SATA drive. The top fan indirectly contributes to cooling. This arrangement of components is less common, but still it is a reliable solution in terms of functionality.

Optimization options

If you find that your hard drive temperature is too high, then you should consider using a standard hard drive cooler. You can usually buy them in stores; in this case, the main culprit of errors is not the optimal location.

Air flow: measuring and comparing results

Naturally, we wanted to confirm the arguments made on the previous pages by using a number of different scenarios for installing a cooling system. We used an Antec Lanboy Air case, covering some of the vents with cardboard to make it difficult for air to pass through. Lanboy Air case is designed for mounting the power supply both above and below. The results speak for themselves.

Looking at the temperature of the air exiting the PSU, we can see the biggest advantage of having the PSU installed on the bottom of our test case.

Here we can see that assemblies cooled by a downward airflow cooler actually benefit from side ventilation.

Airflow: Provide proper ventilation for graphics cards

Ventilation and cooling of video cards

Before you rush to buy the fastest graphics cards you can afford online, be sure to select the models (and motherboard) that will help you create proper airflow.

Your best bet is a card that can draw all the heat out the back of the case, even if it has a centrifugal fan, which tends to make a lot of noise. Typically the reference models from AMD and nVidia are good examples, although the Radeon HD 6990, GeForce GTX 590, and low-end GeForce graphics cards do not fall under our total mass of preference for direct heat dissipation.

This is what happens when too much heat builds up. The presence of perforations on the slot covers could have prevented the sticker from peeling off the video card. Well, henceforth you will not make a similar mistake. The eight hundred watts of heat dissipated in this package is bound to adversely affect the components.

Schematic illustrations

As long as the video card has the ability to remove heat from the case, the temperature values ​​will remain at an acceptable level. Even a multi-GPU array has access to sufficient airflow to operate within safe allowable limits as long as there is enough space between graphics cards. If you want to take advantage of the CrossFire or SLI configuration, buy a motherboard with at least one expansion slot between the installed dual-slot cards.

If the graphics cards are placed too close together, as shown in the picture above, then a locked card can easily overheat, even under moderate load. After all, its fan can't draw in enough air to keep the GPU temperature within acceptable limits.

A similar situation occurs when it comes to graphics cards equipped with axial fans. Although they are quiet, these devices are more likely to allow nearby hot air to enter your chassis rather than expel air out of it, resulting in unwanted heat build-up.

In many cases, a side fan can solve the problem. Even despite the fact that this type of fan is constantly criticized, the efficiency of such a device (and as a result, also an improvement in the cooling of the video card) can be measured and really felt.

Optimization options

There are interesting alternatives to regular slot covers - keep this in mind if you're having trouble cooling. With the slot cooler, heat build-up can be minimized to some extent, even after you have assembled your computer.

Waiting for the second part of the article

While power users now smile indulgently when they read about simple build errors, we know that sooner or later everyone makes mistakes. PCs are, of course, not cheap at all, and even when you save money by assembling a computer yourself, an enthusiast-oriented machine can easily beat the several thousand dollar price level.

This is why it is so important to think carefully about your build plan before you start buying components. First, find a suitable enclosure, and then check if the components of your choice can be placed inside it. Don't dismiss old solutions like side fans. We were able to show that they can actually contribute to better cooling. Sometimes we just had to take measurements to prove our point.

What awaits us in the second part of this article?

If you are not planning to turn your new computer into a Hot Dog Machine, then in part two we will talk about how to choose the right fan and then make sure our CPU cooler is installed properly. This means that we will provide a guide to applying thermal paste especially for beginners.

We also show you how to cool the "unaffected" overclocked GeForce GTX 480 to 64 ° C for a budget of only € 12, while maintaining 38 dB (A) noise levels. Finally, we equip our low-profile and near-silent Radeon HD 6850 with 60mm fans to keep it cool.

Electric motors used in computer fans are built on a slightly different principle. According to their name, such motors do not have a brush-collector unit with sliding contacts.

In the previous section of the article, it was explained that brushed motors are driven by a central part with an electromagnet and a winding, while permanent magnets are stationary. Brushless motors, on the other hand, are designed in such a way that the inductor in the form of magnets is in the rotor and the winding is in the stator.

In the case of computer coolers, magnets are attached to an impeller with fan blades and a fixed shaft. This design in the system under consideration will be considered a rotor. Then the stator will be the fan frame with the necessary components, such as a stationary electromagnet, and the junction of the stator and rotor, in which the bearings of interest are located.
Brushless motors can have a different number of coils, in the fans of interest to us there are usually eight of them. If you disassemble such a fan, four T-shaped metal “hands” will immediately catch your eye, and each of them will have a double winding (in the next photo, you can easily distinguish the red and yellow copper wires).
Naturally, fans do not use bulky wires to power the various coils, but rather compact printed circuit boards. Although there are complex and functional brushless motors with a large number of windings and corresponding phases (for example, HDD motors are usually three-phase), simple two-phase motors are installed in fans. To start and rotate, they only need the sine and cosine components of the current. The very driving force of brushless motors does not differ from collector motors, only in brushless electric motors, voltage is applied to the windings themselves in such a way as to repel the permanent magnet of the rotor and maintain a constant rotation of the latter.
The simplified brushless fans are equipped with only two wires for power supply. Additionally, a third wire may be present, which is necessary for the feedback of the cooler with (or another board, if we are talking, for example, about). The readings of such fans are converted by special chips into the number of revolutions per minute (RPM), and this human-readable number can be read in the BIOS or using special monitoring programs. The addition of such a possibility somewhat increases the cost of the circuit, but today a fan without a speed sensor can be found only on the most budgetary computer devices.

Once again, this is a very simplified description of the operation algorithm of brushless motors, but it is quite enough to understand the operation of computer fans.

It is worth mentioning the advantages of motors of this type over collector motors: they are much less noisy, no sparks can arise from contact contacts, and the reliability of devices of this type is noticeably higher.

How to properly organize cooling in a gaming computer

The use of even the most efficient coolers may turn out to be useless if the air ventilation system is poorly thought out in the computer case. Therefore, the correct installation of fans and accessories is a mandatory requirement when assembling a system unit. Let's explore this question using the example of one productive gaming PC.

⇣ Contents

This article is a continuation of a series of introductory materials on assembling system units. If you remember, last year there was a step-by-step instruction "", which describes in detail all the main points for creating and testing a PC. However, as is often the case, when assembling a system unit, nuances play an important role. In particular, properly installing the fans in the chassis will increase the efficiency of all cooling systems, as well as reduce the heating of the main components of the computer. It is this question that is discussed in the article below.

I warn you right away that the experiment was carried out on the basis of one typical assembly using an ATX motherboard and a Midi-Tower case. The option presented in the article is considered the most common, although we all know perfectly well that computers are different, and therefore systems with the same level of performance can be assembled in dozens (if not hundreds) of different ways. That is why the above results are relevant exclusively for the considered configuration. Judge for yourself: computer cases, even within the same form factor, have different volumes and number of seats for installing fans, and video cards, even using the same GPU, are assembled on printed circuit boards of different lengths and equipped with coolers with different numbers of heat pipes and fans. Nevertheless, our small experiment will allow us to draw certain conclusions.

An important "detail" of the system unit is the central processor Core i7-8700K. A detailed review of this six-core is located, so I will not repeat myself once again. Let me just note that cooling the flagship for the LGA1151-v2 platform is not an easy task even for the most efficient coolers and liquid cooling systems.

The system was installed 16 GB of DDR4-2666 RAM. The Windows 10 operating system was written to a Western Digital WDS100T1B0A solid state drive. You can get acquainted with the review of this SSD.

MSI GeForce GTX 1080 Ti GAMING X TRIO

The MSI GeForce GTX 1080 Ti GAMING X TRIO graphics card, as the name suggests, features a TRI-FROZR cooler with three TORX 2.0 fans. According to the manufacturer, these impellers create 22% more airflow while remaining virtually silent. Low volume, as stated on the official MSI website, is ensured, among other things, through the use of double-row bearings. Note that the radiator of the cooling system, and its ribs are made in the form of waves. According to the manufacturer, this design increases the total dissipation area by 10%. The radiator also comes into contact with the elements of the power subsystem. MSI GeForce GTX 1080 Ti GAMING X TRIO memory chips are additionally cooled with a special plate.

The accelerator fans start rotating only when the chip temperature reaches 60 degrees Celsius. On an open stand, the maximum GPU temperature was only 67 degrees Celsius. At the same time, the fans of the cooling system spun up by a maximum of 47% - this is about 1250 rpm. The real GPU frequency in the default mode was stable at 1962 MHz. As you can see, the MSI GeForce GTX 1080 Ti GAMING X TRIO has a decent factory overclock.

The adapter is equipped with a massive backplate that increases the rigidity of the structure. The back of the graphics card has an L-shaped strip with built-in Mystic Light LED backlighting. The user, using the application of the same name, can separately configure three zones of the glow. In addition, the fans are framed by two rows of symmetrical dragon claw lights.

According to the technical specifications, MSI GeForce GTX 1080 Ti GAMING X TRIO has three operating modes: Silent Mode - 1480 (1582) MHz for the core and 11016 MHz for memory; Gaming Mode - 1544 (1657) for the core and 11016 MHz for memory; OC Mode - 1569 (1683) MHz core and 11124 MHz memory. By default, the video card has game mode enabled.

You can familiarize yourself with the performance level of the reference GeForce GTX 1080 Ti. Also, MSI GeForce GTX 1080 Ti Lightning Z was released on our website. This graphics adapter is also equipped with a TRI-FROZR cooling system.

The assembly is based on the MSI Z370 GAMING M5 ATX form factor motherboard. This is a slightly modified version of the MSI Z270 GAMING M5 board, which was released on our website last spring. The device is perfect for overclocked Coffee Lake K-processors, as the digital power converter Digitall Power consists of five dual phases, implemented in a 4 + 1 scheme. Four channels are directly responsible for the operation of the CPU, another one for the integrated graphics.

All components of the power circuits comply with the Military Class 6 standard - this applies to both titanium core chokes and Dark CAP capacitors with at least ten years of service life, as well as energy efficient Dark Choke coils. And DIMM slots for installing RAM and PEG ports for installing video cards are clad in a metallized Steel Armor case, and also have additional soldering points on the back of the board. Additional isolation of the tracks is applied to the RAM, and each memory channel is wired in its own layer of PCB, which, according to the manufacturer, allows to achieve a "cleaner" signal and increase the stability of the overclocking of DDR4 modules.

Of the useful things, I note the presence of two M.2 connectors at once, which support the installation of PCI Express and SATA 6 Gb / s drives. The top port can accommodate SSDs up to 110mm in length, and the bottom port up to 80mm. The second port is additionally equipped with a metal heatsink M.2 Shield, which is in contact with the drive using a thermal pad.

The Killer E2500 gigabit controller is responsible for the wired connection in the MSI Z370 GAMING M5, and the Realtek 1220 chip is responsible for the sound. The Audio Boost 4 sound path received Chemi-Con capacitors, a dual headphone amplifier with an impedance of up to 600 ohms, a front dedicated audio output and gold-plated audio connectors. All components of the sound zone are isolated from the rest of the board with a non-conductive backlit strip.

Mystic Light motherboard backlight supports 16.8 million colors and works in 17 modes. An RGB strip can be connected to the motherboard, the corresponding 4-pin connector is soldered at the bottom of the board. By the way, the device comes with an 800 mm extension cord with a splitter for connecting an additional LED strip.

The board is equipped with six 4-pin connectors for connecting fans. The total number is selected optimally, the location is also. The PUMP_FAN port, soldered next to the DIMM, supports the connection of impellers or a pump with a current of up to 2 A. The location is again very good, since it is easy to connect a pump to this connector from both an unattended LSS and a custom system assembled by hand. The system cleverly manages including "Carlsons" with a 3-pin connector. The frequency is regulated both by the number of revolutions per minute and by the voltage. It is possible to completely stop the fans.

Finally, I would like to note two more very useful features of the MSI Z370 GAMING M5. The first is the presence of the POST indicator. The second is the EZ Debug LED block located next to the PUMP_FAN connector. It clearly demonstrates at what stage the system is booted: at the stage of initializing the processor, RAM, video card or drive.

The choice for Thermaltake Core X31 was not accidental. Here is a Tower case that meets all modern trends. The power supply is installed from below and is isolated with a metal shutter. There is a basket for installing three drives of 2.5 '' and 3.5 '' form factors, but HDD and SSD can be mounted on the barrier wall. There is a basket for two 5.25 "devices. Without them, nine 120mm or 140mm fans can be installed in the case. As you can see, Thermaltake Core X31 allows you to fully customize your system. For example, on the basis of this case, it is quite possible to assemble a PC with two 360-mm LSS radiators.

The device turned out to be very spacious. There is plenty of room behind the chassis for cable routing. Even with careless assembly, the side cover will close easily. The space for the hardware allows you to use processor coolers up to 180 mm in height, video cards up to 420 mm in length, and power supplies up to 220 mm in length.

The bottom and front panel are equipped with dust filters. The top cover is equipped with a mesh mat, which also keeps dust out and makes it easier to install case fans and water cooling systems.

Often used to build a large radiator heat pipes(English: heat pipe) - hermetically sealed and specially arranged metal tubes (usually copper). They transfer heat very efficiently from one end to the other: thus, even the farthest fins of a large radiator work effectively in cooling. This is how the popular cooler works.

To cool modern high-performance GPUs, the same methods are used: large radiators, copper cores for cooling systems or all-copper radiators, heat pipes to transfer heat to additional radiators:

The recommendations for selection are the same: use slow and large fans, as large as possible radiators. This is how the popular cooling systems for video cards and the Zalman VF900 look like:

Usually, fans of video card cooling systems only stirred the air inside the system unit, which is not very effective in terms of cooling the entire computer. Only quite recently, cooling systems began to be used to cool video cards, which carry hot air out of the case: the first were and, a similar design, from the brand:

Such cooling systems are installed on the most powerful modern video cards (nVidia GeForce 8800, ATI x1800XT and older). This design is often more justified from the point of view of the correct organization of air flows inside the computer case than traditional schemes. Organization of air flows

Modern standards for the design of computer cases, among other things, regulate the way of building a cooling system. Since the release of which was launched in 1997, the technology of cooling the computer with a through air flow directed from the front wall of the case to the back has been introduced (in addition, air for cooling is sucked in through the left wall):

Those interested in the details refer to the latest versions of the ATX standard.

At least one fan is installed in the computer's power supply (many modern models have two fans, which can significantly reduce the rotational speed of each of them, and, therefore, the noise during operation). Additional fans can be installed anywhere inside the computer to enhance airflow. Be sure to follow the rule: on the front and left side walls, the air is forced inside the case, on the back wall, hot air is thrown out... You also need to make sure that the flow of hot air from the back of the computer does not go directly into the air intake on the left side of the computer (this happens at certain positions of the system unit relative to the walls of the room and furniture). Which fans to install depends primarily on the presence of appropriate mounts in the walls of the case. Fan noise is mainly determined by its rotation speed (see section), therefore it is recommended to use slow (quiet) fan models. With equal installation dimensions and rotational speed, the fans on the back of the case subjectively make a little less noise than the front ones: firstly, they are located farther from the user, and secondly, there are almost transparent grilles behind the case, while in front there are various decorative elements. Often, noise is created due to the air flow around the elements of the front panel: if the transferred volume of air flow exceeds a certain limit, vortex turbulent currents form on the front panel of the computer case, which create a characteristic noise (it resembles the hiss of a vacuum cleaner, but much quieter).

Choosing a computer case

Almost the overwhelming majority of cases for computers on the market today comply with one of the versions of the ATX standard, including in terms of cooling. The cheapest enclosures come with neither a power supply unit nor additional accessories. More expensive cases are equipped with fans for cooling the case, less often with adapters for connecting fans in various ways; sometimes even a special controller equipped with temperature sensors, which allows you to smoothly adjust the rotation speed of one or more fans depending on the temperature of the main units (see for example). The power supply unit is not always included in the kit: many buyers prefer to choose a power supply unit on their own. Among other options for additional equipment, it is worth noting special mounts for side walls, hard drives, optical drives, expansion cards, which allow you to assemble a computer without a screwdriver; Dust filters that prevent dirt from entering the computer through the ventilation holes; various nozzles for directing air flows inside the housing. Exploring the fan

To transfer air in cooling systems, use fans(English: fan).

Fan device

The fan consists of a casing (usually in the form of a frame), an electric motor and an impeller, fixed with bearings on the same axis with the motor:

The reliability of the fan depends on the type of bearings installed. Manufacturers claim this typical MTBF (years based on 24/7 operation):

Taking into account the obsolescence of computer equipment (for home and office use it is 2-3 years), fans with ball bearings can be considered "eternal": their life is not less than the typical life of a computer. For more serious applications, where the computer has to work around the clock for many years, it is worth choosing more reliable fans.

Many have come across old fans in which the sleeve bearings have worn out: the impeller shaft rattles and vibrates during operation, making a characteristic roaring sound. In principle, such a bearing can be repaired by lubricating it with solid lubricant - but how many would agree to repair a fan that costs only a couple of dollars?

Fan characteristics

Fans differ in size and thickness: usually computers have standard sizes 40 × 40 × 10 mm for cooling video cards and hard drive pockets, as well as 80 × 80 × 25, 92 × 92 × 25, 120 × 120 × 25 mm for cooling the case. The fans also differ in the type and design of the installed electric motors: they consume different currents and provide different speed of rotation of the impeller. The performance depends on the size of the fan and the speed of rotation of the impeller blades: the generated static pressure and the maximum volume of transported air.

The volume of air carried by the fan (flow rate) is measured in cubic meters per minute or cubic feet per minute (CFM). The fan performance indicated in the characteristics is measured at zero pressure: the fan is operating in an open space. Inside the computer case, the fan blows into the system unit of a certain size, therefore it creates excess pressure in the serviced volume. Naturally, the volumetric capacity will be approximately inversely proportional to the generated pressure. Specific view consumption characteristics depends on the shape of the impeller used and other parameters of the particular model. For example, the corresponding graph for a fan:

The conclusion is simple: the more intensively the fans at the back of the computer case, the more air can be pumped through the entire system, and the more efficient the cooling will be.

Fan noise level

The noise level generated by the fan during operation depends on its various characteristics (for more details on the reasons for its occurrence, see the article). It is not difficult to establish the relationship between performance and fan noise. On the website of a large manufacturer of popular cooling systems, we see: many fans of the same size are equipped with different electric motors, which are designed for different rotational speeds. Since the impeller is used the same, we get the data of interest to us: the characteristics of the same fan at different speeds. We draw up a table for the three most common standard sizes: thickness 25 mm, and.

The most popular fan types are in bold.

Having calculated the coefficient of proportionality of the air flow and the noise level to the rpm, we see almost complete coincidence. To clear our conscience, we consider deviations from the average: less than 5%. Thus, we got three linear dependences, 5 points each. It is not God only knows what statistics, but for a linear relationship this is enough: the hypothesis is considered confirmed.

The volumetric performance of the fan is proportional to the number of revolutions of the impeller, the same is true for the noise level..

Using this hypothesis, we can extrapolate the results obtained by the method of least squares (OLS): in the table, these values ​​are shown in italics. It should be remembered, however, that the scope of this model is limited. The investigated dependence is linear in a certain range of rotation speeds; it is logical to assume that the linear nature of the dependence will remain in some vicinity of this range; but at very high and very low speeds, the picture can change significantly.

Now let's consider a line of fans from another manufacturer:, and. Let's make a similar plate:

Calculated data are highlighted in italics.
As mentioned above, if the fan speed values ​​differ significantly from those investigated, the linear model may be incorrect. Extrapolated values ​​are to be understood as approximate estimates.

Let's pay attention to two circumstances. Firstly, GlacialTech fans run slower, and secondly, they are more efficient. Obviously, this is the result of using an impeller with a more complex blade shape: even at the same speed, the GlacialTech fan carries more air than the Titan: see the graph growth... A the noise level at the same speed is approximately equal: The proportion is maintained even for fans from different manufacturers with different impeller shapes.

It should be understood that the real noise characteristics of the fan depend on its technical design, the generated pressure, the volume of pumped air, on the type and shape of obstacles in the path of air flows; that is, on the type of computer case. Since the cases are very different, it is impossible to directly apply the quantitative characteristics of the fans measured under ideal conditions - they can only be compared with each other for different fan models.

Fan price categories

Consider the cost factor. For example, let's take in the same online store and: the results are written in the tables above (fans with two ball bearings were considered). As you can see, the fans of these two manufacturers belong to two different classes: GlacialTech operate at lower speeds, therefore they are less noisy; at the same speed they are more efficient than the Titan - but they are always more expensive by a dollar or two. If you need to build the least noisy cooling system (for example, for a home computer), you will have to fork out for more expensive fans with complex blade shapes. In the absence of such stringent requirements or on a limited budget (for example, for an office computer), simpler fans are fine. The different type of impeller suspension used in fans (see the section for more details) also affects the cost: the fan is more expensive, the more complex bearings are used.

The beveled corners on one side serve as the key for the connector. The wires are connected as follows: two central ones - "ground", common contact (black wire); +5 V - red, +12 V - yellow. To power the fan through the molex connector, only two wires are used, usually black ("ground") and red (supply voltage). By connecting them to different pins of the connector, you can get different fan speeds. A standard voltage of 12 volts will start the fan at nominal speed, a voltage of 5-7 volts will provide about half the rotational speed. It is preferable to use a higher voltage, since not every electric motor is able to reliably start at too low supply voltage.

Experience shows that fan speed when connected to +5 V, +6 V and +7 V is approximately the same(with an accuracy of 10%, which is comparable to the measurement accuracy: the rotation speed is constantly changing and depends on many factors, such as air temperature, the slightest draft in the room, etc.)

I remind you that the manufacturer guarantees the stable operation of its devices only when using a standard supply voltage... But, as practice shows, the overwhelming majority of fans start up perfectly even at reduced voltage.

The contacts are fixed in the plastic part of the connector using a pair of bending metal "tendrils". It is not difficult to remove the contact by pressing down the protruding parts with a thin awl or a small screwdriver. After that, the "antennae" must again be bent to the sides, and insert the contact into the corresponding socket of the plastic part of the connector:

Sometimes coolers and fans are equipped with two connectors: molex-connected in parallel and three- (or four-) pin. In this case you need to connect power only through one of them:

In some cases, more than one molex connector is used, but a pair of "mom-dad": this way you can connect the fan to the same wire from the power supply that powers the hard disk or optical drive. If you swap the pins in the connector to get a non-standard voltage on the fan, pay special attention to swap the pins in the second connector in exactly the same order. Failure to do so could result in incorrect supply voltage to the hard disk or optical drive, which will most likely lead to their instant failure.

In three-pin connectors, the key for installation is a pair of protruding guides on one side:

The counterpart is located on the contact pad, when connected, it enters between the guides, also acting as a latch. The corresponding connectors for powering the fans are located on the motherboard (as a rule, there are several in different places on the board) or on the board of a special controller that controls the fans:

In addition to "ground" (black wire) and +12 V (usually red, less often: yellow), there is also a tachometer contact: it is used to control the fan speed (white, blue, yellow or green wire). If you do not need the ability to control the fan speed, then this contact can be left unconnected. If the fan is powered separately (for example, through the molex connector), it is permissible to connect only the RPM control contact and the common wire using a three-pin connector - this circuit is often used to monitor the fan rotation speed of the power supply, which is powered and controlled by the internal power supply circuits.

Four-pin connectors have appeared relatively recently on motherboards with LGA 775 and socket AM2 processor sockets. They differ in the presence of an additional fourth contact, while fully mechanically and electrically compatible with three-pin connectors:

Two the same a fan with three-pin connectors can be connected in series to one power connector. Thus, each of the electric motors will have 6 V supply voltage, both fans will rotate at half speed. For such a connection, it is convenient to use the fan power connectors: the contacts can be easily removed from the plastic case by pressing the fixing “tab” with a screwdriver. The connection diagram is shown in the figure below. One of the connectors plugs into the motherboard as usual: it will supply power to both fans. In the second connector, using a piece of wire, you need to short-circuit two contacts, and then insulate it with tape or electrical tape:

It is strongly discouraged to connect two different electric motors in this way.: due to the inequality of electrical characteristics in different operating modes (starting, acceleration, stable rotation), one of the fans may not start at all (which is fraught with the failure of the electric motor) or require an excessively large current to start (fraught with failure of the control circuits).

Often, fixed or variable resistors connected in series in the power circuit are tried on to limit the fan speed. By changing the resistance of the variable resistor, you can adjust the rotation speed: this is how many manual fan speed controllers work. When designing such a circuit, it must be remembered that, firstly, the resistors heat up, dissipating part of the electrical power in the form of heat - this does not contribute to more efficient cooling; secondly, the electrical characteristics of the electric motor in different modes of operation (start-up, acceleration, stable rotation) are not the same, the parameters of the resistor must be selected taking into account all these modes. To select the parameters of the resistor, it is enough to know Ohm's law; you need to use resistors designed for a current no less than the electric motor consumes. However, I personally do not welcome manual control of the cooling, as I believe that a computer is a perfectly suitable device to control the cooling system automatically, without user intervention.

Fan monitoring and control

Most modern motherboards allow you to control the speed of the fans connected to some 3- or 4-pin connectors. Moreover, some of the connectors support software control of the rotational speed of the connected fan. Not all connectors on the board provide such capabilities: for example, the popular Asus A8N-E board has five connectors for powering fans, only three of them support rotation speed control (CPU, CHIP, CHA1), and only one fan speed control (CPU); Asus P5B motherboard has four connectors, all four support rotation speed control, rotation speed control has two channels: CPU, CASE1 / 2 (the speed of two case fans changes synchronously). The number of connectors with the ability to control or control the rotational speed does not depend on the chipset or south bridge used, but on the specific motherboard model: models from different manufacturers may differ in this respect. Often, motherboard designers deliberately deprive cheaper models of fan speed control capabilities. For example, the motherboard for Intel Pentiun 4 processors Asus P4P800 SE is able to regulate the speed of the processor cooler, but its cheaper version Asus P4P800-X is not. In this case, you can use special devices that are able to control the speed of several fans (and, usually, provide for the connection of a number of temperature sensors) - they appear more and more in the modern market.

You can control the fan speed values ​​using BIOS Setup. As a rule, if the motherboard supports changing the fan speed, here in the BIOS Setup you can configure the parameters of the speed control algorithm. The set of parameters is different for different motherboards; usually the algorithm uses the readings of thermal sensors built into the processor and motherboard. There are a number of programs for different operating systems that allow you to control and adjust the fan speed, as well as monitor the temperature of various components inside the computer. Some motherboard manufacturers bundle their products with proprietary Windows programs: Asus PC Probe, MSI CoreCenter, Abit µGuru, Gigabyte EasyTune, Foxconn SuperStep, etc. Several universal programs are distributed, among them: (shareware, $ 20-30), (distributed free of charge, has not been updated since 2004). The most popular program of this class is:

These programs allow you to monitor a range of temperature sensors that are installed in modern processors, motherboards, video cards and hard drives. The program also monitors the rotation speed of the fans that are connected to the motherboard connectors with appropriate support. Finally, the program is able to automatically adjust the fan speed depending on the temperature of the monitored objects (if the motherboard manufacturer has implemented hardware support for this feature). In the above figure, the program is configured to control only the processor fan: at a low CPU temperature (36 ° C), it rotates at about 1000 rpm, which is 35% of the maximum speed (2800 rpm). Setting up such programs comes down to three steps:

1. determining which of the motherboard controller channels the fans are connected to, and which of them can be controlled by software;
2. an indication of which of the temperatures should affect the speed of the various fans;
3. setting temperature thresholds for each temperature sensor and a range of operating speeds for fans.

Many programs for testing and fine-tuning computers also have monitoring capabilities:, etc.

Many modern video cards also allow you to adjust the fan speed of the cooling system depending on the temperature of the GPU. With the help of special programs, you can even change the settings of the cooling mechanism, reducing the noise level from the video card in the absence of load. This is how the optimal settings for the HIS X800GTO IceQ II video card look like in the program:

Passive cooling

Passive cooling systems are usually called those that do not contain fans. Individual computer components can be satisfied with passive cooling, provided that their heatsinks are placed in a sufficient air flow created by "foreign" fans: for example, a chipset's microcircuit is often cooled by a large heatsink located near the place where the processor cooler is installed. Passive cooling systems for video cards are also popular, for example:

Obviously, the more radiators one fan has to blow through, the greater the flow resistance it needs to overcome; thus, with an increase in the number of radiators, it is often necessary to increase the rotation speed of the impeller. It is more efficient to use a lot of low speed large diameter fans, and passive cooling systems are preferable to avoid. Despite the fact that there are passive heatsinks for processors, video cards with passive cooling, even power supplies without fans (FSP Zen), an attempt to build a computer with no fans at all from all these components will certainly lead to constant overheating. Because a modern high-performance computer dissipates too much heat to be cooled by passive systems alone. Due to the low thermal conductivity of air, it is difficult to organize effective passive cooling for the entire computer, except perhaps to turn the entire computer case into a radiator, as is done in:

Compare the case-radiator in the photo with the case of a regular computer!

Perhaps completely passive cooling will be sufficient for low-power specialized computers (for Internet access, for listening to music and watching videos, etc.)

In the old days, when the power consumption of processors had not yet reached critical values ​​- a small radiator was enough to cool them down - the question "what will the computer do when there is nothing to do?" The solution was simple: while it is not necessary to execute user commands or running programs, the OS gives the processor a NOP command (No OPeration, no operation). This command causes the processor to perform a meaningless, ineffectual operation, the result of which is ignored. This takes not only time, but also electricity, which, in turn, is converted into heat. A typical home or office computer, in the absence of resource-intensive tasks, is usually only 10% loaded - anyone can verify this by launching the Windows Task Manager and observing the Timeline of the CPU (Central Processing Unit) load. Thus, with the old approach, about 90% of the CPU time was wasted: the CPU was busy executing commands that no one needed. Newer operating systems (Windows 2000 and later) act more sensibly in a similar situation: using the HLT (Halt, halt) command, the processor stops completely for a short time - this, obviously, allows to reduce power consumption and processor temperature in the absence of resource-intensive tasks.

Experienced computer scientists can recall a number of programs for "software cooling of the processor": while running under Windows 95/98 / ME, they stopped the processor using HLT, instead of repeating meaningless NOPs, which reduced the temperature of the processor in the absence of computational tasks. Accordingly, the use of such programs under Windows 2000 and newer operating systems is meaningless.

Modern processors consume so much energy (which means: they dissipate it in the form of heat, that is, they heat up) that the developers have created additional technical tools to combat possible overheating, as well as tools that increase the efficiency of saving mechanisms when the computer is idle.

Thermal protection of the processor

To protect the processor from overheating and failure, the so-called thermal throttling is used (usually not translated: throttling). The essence of this mechanism is simple: if the processor temperature exceeds the allowable temperature, the processor is forced to stop with the HLT command so that the crystal can cool down. In early implementations of this mechanism, through BIOS Setup, it was possible to configure how much of the time the processor would be idle (parameter CPU Throttling Duty Cycle: xx%); new implementations "slow down" the processor automatically until the crystal temperature drops to an acceptable level. Of course, the user is interested in the processor not being cooled down (literally!), But doing useful work - for this you need to use a sufficiently effective cooling system. You can check if the processor's thermal protection mechanism (throttling) is turned on using special utilities, for example:

Minimizing energy consumption

Almost all modern processors support special technologies to reduce energy consumption (and, accordingly, heating). Different manufacturers call such technologies differently, for example: Enhanced Intel SpeedStep Technology (EIST), AMD Cool'n'Quiet (CnQ, C&Q) - but they work essentially the same way. When the computer is idle and the processor is not loaded with computational tasks, the processor clock speed and voltage are reduced. Both reduce the power consumption of the processor, which in turn reduces heat generation. As soon as the processor load increases, the full processor speed is automatically restored: the operation of such a power-saving scheme is completely transparent to the user and the programs being launched. To enable such a system, you need:

1. enable the use of a supported technology in BIOS Setup;
2. install the appropriate drivers in the operating system (usually a processor driver);
3. in the Windows Control Panel, in the Power Management section, on the Power Schemes tab, select the Minimal Power Management scheme from the list.

For example, for an Asus A8N-E motherboard with a processor you need (detailed instructions are given in the User Guide):

1. in BIOS Setup, in the Advanced> CPU Configuration> AMD CPU Cool & Quiet Configuration section, switch the Cool N "Quiet parameter to Enabled; and in the Power section, switch the ACPI 2.0 Support parameter to Yes;
2. install ;
3. see above.

You can check that the processor frequency is changing using any program that displays the processor's frequency: from specialized types, up to the Windows Control Panel, System section:

AMD Cool "n" Quiet in Action: CPU Current (994 MHz) Less Than Nominal (1.8 GHz)

Often, motherboard manufacturers additionally complete their products with visual programs that clearly demonstrate the operation of the mechanism for changing the frequency and voltage of the processor, for example, Asus Cool & Quiet:

The processor frequency changes from the maximum (in the presence of a computational load), to a certain minimum (in the absence of a CPU load).

RMClock utility

During the development of a set of programs for comprehensive testing of processors, (RightMark CPU Clock / Power Utility) was created: it is designed to monitor, configure and manage energy-saving capabilities of modern processors. The utility supports all modern processors and a variety of power management systems (frequency, voltage ...) The program allows you to monitor the occurrence of throttling, changes in the frequency and voltage of the processor. Using RMClock, you can configure and use everything that standard tools allow: BIOS Setup, power management from the OS side using the processor driver. But the capabilities of this utility are much wider: with its help, you can configure a number of parameters that are not available for customization in a standard way. This is especially important when using overclocked systems, when the processor runs faster than the nominal frequency.

Auto overclocking video card

A similar method is used by the developers of video cards: the full power of the graphics processor is needed only in 3D mode, and a modern graphics chip can cope with a desktop in 2D mode even at a reduced frequency. Many modern video cards are configured so that the graphics chip serves a desktop (2D mode) with reduced frequency, power consumption and heat dissipation; accordingly, the cooling fan spins more slowly and makes less noise. The video card starts working at full capacity only when you run 3D applications, for example, computer games. Similar logic can be implemented in software using various utilities for fine-tuning and overclocking video cards. For example, this is how the automatic overclocking settings in the program for the HIS X800GTO IceQ II video card look like:

Quiet computer: myth or reality?

From the user's point of view, a computer is considered sufficiently quiet if its noise does not exceed the surrounding background noise. During the day, taking into account the noise of the street outside the window, as well as the noise in the office or at work, the computer is allowed to make a little more noise. A home computer that you plan to use around the clock should be quieter at night. As practice has shown, almost any modern powerful computer can be made to work quite quietly. I will describe a few examples from my practice.

Example 1: Intel Pentium 4 Platform

In my office I use 10 Intel Pentium 4 3.0 GHz computers with standard CPU coolers. All machines are assembled in inexpensive Fortex cases up to $ 30, Chieftec 310-102 power supplies (310 W, 1 fan 80 × 80 × 25 mm) are installed. In each case, a 80 × 80 × 25 mm fan (3000 rpm, noise 33 dBA) was installed on the rear wall - they were replaced by fans with the same performance 120 × 120 × 25 mm (950 rpm, noise 19 dBA) ). In the file server of the local network, for additional cooling of hard drives, 2 fans 80 × 80 × 25 mm are installed on the front wall, connected in series (speed 1500 rpm, noise 20 dBA). Most computers use the Asus P4P800 SE motherboard, which is able to regulate the speed of the CPU cooler. The two computers are equipped with cheaper Asus P4P800-X motherboards, where the cooler speed is not regulated; to reduce the noise from these machines, the CPU coolers were replaced (1900 rpm, 20 dBA noise).
Result: computers are quieter than air conditioners; they are practically inaudible.

Example 2: Intel Core 2 Duo Platform

A home computer based on a new Intel Core 2 Duo E6400 (2.13 GHz) processor with a standard processor cooler was assembled in an inexpensive aigo case at the price of $ 25, a Chieftec 360-102DF power supply unit (360 W, 2 fans 80 × 80 × 25 mm) was installed. In the front and rear walls of the case, 2 fans 80 × 80 × 25 mm are installed, connected in series (the speed is adjustable, from 750 to 1500 rpm, the noise is up to 20 dBA). Used motherboard Asus P5B, which is able to regulate the speed of the processor cooler and case fans. A video card with a passive cooling system is installed.
Result: the computer makes such a noise that during the day it is not heard behind the usual noise in the apartment (conversations, steps, the street outside the window, etc.).

Example 3: AMD Athlon 64 Platform

My home computer on an AMD Athlon 64 3000+ (1.8 GHz) processor is built in an inexpensive Delux package for up to $ 30, initially it contained a CoolerMaster RS-380 power supply (380 W, 1 fan 80 × 80 × 25 mm) and a GlacialTech SilentBlade video card GT80252BDL-1 connected to +5 V (about 850 rpm, noise less than 17 dBA). Used motherboard Asus A8N-E, which is able to regulate the speed of the processor cooler (up to 2800 rpm, noise up to 26 dBA, in idle mode the cooler rotates about 1000 rpm and makes less than 18 dBA noise). The problem with this motherboard: cooling the nVidia nForce 4 chipset, Asus installs a small 40 × 40 × 10 mm fan with a rotation speed of 5800 rpm, which whistles loudly and unpleasantly (in addition, the fan is equipped with a sliding bearing, which has a very short resource) ... To cool the chipset, a cooler for video cards with a copper radiator was installed, against its background you can clearly hear the positioning clicks of the hard drive heads. A working computer does not interfere with sleeping in the same room where it is installed.
Recently, the video card was replaced by the HIS X800GTO IceQ II, for the installation of which it was necessary to modify the chipset heatsink: bend the edges so that they did not interfere with the installation of a video card with a large cooling fan. Fifteen minutes of work with pliers - and the computer continues to run quietly, even with a fairly powerful video card.

Example 4: AMD Athlon 64 X2 Platform

A home computer based on an AMD Athlon 64 X2 3800+ (2.0 GHz) processor with a processor cooler (up to 1900 rpm, noise up to 20 dBA) is assembled in a 3R System R101 case (included 2 fans 120 × 120 × 25 mm, up to 1500 rpm, installed on the front and rear walls of the case, connected to a standard monitoring and automatic fan control system), an FSP Blue Storm 350 power supply unit (350 W, 1 fan 120 × 120 × 25 mm) is installed. A motherboard (passive cooling of the chipset microcircuits) was used, which is able to regulate the speed of the processor cooler. The video card GeCube Radeon X800XT was used, the cooling system was replaced with Zalman VF900-Cu. A hard drive known for its low noise generation was chosen for the computer.
Result: The computer is so quiet that you can hear the noise of the hard drive motor. A working computer does not interfere with sleeping in the same room where it is installed (the neighbors behind the wall are talking even louder).