If you look at a modern laptop or personal computer, you will surely see the presence of a solid state drive in the accessories list. This form of data storage has been on the market for years, but has only recently been embraced by the industry and consumers as a viable alternative to traditional hard drives.
So, what is an SSD solid state drive and how does it compare to classic hard drives - HDD?
What is a solid state drive
What is this strange word? Solid state? The name comes from the English word "Solid", which means "solid state". The solid state is understood as an electronic circuit, completely built of semiconductors and representing, in fact, an ordinary microcircuit (one green one, with a bunch of incomprehensible “tracks” on it).
semiconductor chip “Hmm, but it was always like this in all the devices that we broke in childhood,” some, and maybe many, thought. But no, or rather, yes, but no. That is, yes, in those devices that you and I broke in childhood, indeed, there were quite often some green microcircuits, but before that, a long time ago, most devices consisted of vacuum tubes, various wires, switches and a bunch of others all sorts of details. A good example of such a device is a transistor radio, copies of which can be remembered by music lovers from the times of the USSR and the early 90s.
So, Solid-state drive is a solid-state drive, a digital data storage device based on a semiconductor memory chip. I won’t delve into the subtleties (yes, I don’t really know these subtleties - hehe), so as not to clog your brain with unnecessary, unnecessary garbage.
The days of vintage transistors are long gone, and nowadays almost all electronic devices are based on semiconductors, including the very radio.
But, if we talk about such a market niche as "data carriers", then, until recently, well-known hard drives ruled the ball, whose principle of operation is based on the interaction of magnetic disks, and not semiconductors, as in SSDs.
Now you can object, they say, such data storages have existed for a long time in the form of flash drives connected to a USB connector. And you are, by and large, right, because SSD and flash use the same type of energy-saving memory circuits that retain their information even when there is no power. The difference lies in the form factor and capacity of the drives, as well as the fact that a flash drive is designed for external use in a computer system, and an SSD is for placement inside a computer, instead of a traditional hard drive, or next to it.
Most SSDs look very similar to classic HDDs, the difference is only in the form factor (roughly speaking, in the size of the seat). Hard drives, as a rule, have a 3.5 '' form factor, and system units of recent years have been equipped with such seats. SSDs have more compact dimensions, respectively, a smaller form factor - 1.8 '' and 2.5 ''. But, this does not mean that such SSDs cannot be installed in old cases, because the compatibility problem is solved with the help of a special carriage, or with the help of improvised means and imagination.
Some SSDs look more like memory card chips than HDDs, because they are simply a chip that has a connector for connecting. These SSDs include M.2 and PCI-Express form factor models.
There are also those that combine the beneficial aspects of HDDs and solid state drives. They have the same form factor and storage capacity as HDDs, but still have some nice SSD abilities.
Why use an SSD
Solid state drives have a number of advantages over magnetic hard drives, and these are due to the fact that SSDs have no moving parts, while HDDs have motors to rotate the magnetic platters and drive heads. All SSD storage is handled by flash memory chips, and this has three distinct advantages:
- Less power consumption- this is a key factor why the use of SSD in portable computers has become so popular, because unlike hard drives, SSD does not require power for motors, respectively, power consumption is significantly reduced;
- Faster access to data- since the drive does not need to spin up the disk and move the heads, data is read and written at an incredibly fast speed, which adds a lot of pleasant sensations to using a PC or laptop;
- High reliability- hard drives are very fragile and sensitive devices to various external factors. Even a slight shake or drop is enough to cause HDD performance problems. Since an SSD has no moving parts and the data is stored on a chip, there is less chance of damage to the drive from an accidental drop or being transported in a car.
Together, these factors are doing what is happening now - the gradual displacement of magnetic hard drives from the market. But, since the cost of SSD is still quite high, the complete migration of users from HDD to SSD will take more than one year, or even decades. By the way, about this.
Why SSD is not used on all PCs
The main limiting factor in the use of SSDs in laptops and desktops is their high cost. Of course, SSDs have become more affordable in recent years as the price of devices has come down to reasonable levels, but one megabyte on an SSD is still about three times more expensive than the same megabyte on an HDD. And even more, because the higher the capacity of the disk, the greater the difference in price becomes.
Capacity is also an important factor in the adoption of SSDs as the only uncontested storage technology. The average laptop equipped with an SSD will have between 128GB and 256GB of storage. This is roughly equivalent to what was installed in laptops a few years ago - today most laptops are equipped with a 500 GB HDD or more. Desktop systems have an even greater imbalance between SSDs and hard drives, as the average PC is equipped with a 1TB HDD.
Therefore, at the moment, a complete transition of users to SSD is not appropriate, due to the high cost and small volume. But, in fact, the matter is even more likely in the first than in the second, because there are also 4 GB SSDs, but they are worth quite a serious investment. In this regard, the second reason rather follows from the first - a very high price for devices.
We have long been accustomed to hard drives that store our files, documents, videos, images, and everything in general. Hard drives have been around for a very long time. Back in 1956, IBM created a drive that rightfully bears the name of a hard drive. But a deeper and more standardized implementation of these information keepers occurred, of course, in connection with the growing popularity of personal computers.
At first, hard drives were bulky, extremely noisy and had only about 5-50 MB of available space, which, by the way, was enough at that time to install the operating system and all work applications, as well as a set of personal files.
Subsequently, the drives acquired the 3.5” desktop form factor that is still popular to this day, the number of vendors producing these products has decreased, and the volume of drives has grown year by year and has hundreds of megabytes, gigabytes, tens of them, and now thousands of gigabytes per one device.
Hard drives are used everywhere, in almost all computers, at one time there was an attempt to use them even in mobile phones, because at that time, Flash-memory chips were too expensive, unreliable and significantly lost in volume.
The principle of operation has not changed, in fact, for decades. Inside any HDD there is an engine, reading heads and magnetic plates. In other words, mechanics controlled by electronics. Moreover, all this must be in sterile conditions, and the safety of information depends on hundreds of different factors, which is why these devices are sensitive to many external manifestations of exposure.
The evolution of storage systems and the arrivalSSD.
Over time, not only the volume, but also the speed of hard drives grew, new communication interfaces came out, until, finally, they reached a logical "dead end" of development in their speed indicators. As much as we would like to, but it is almost impossible to create a very fast hard drive. Of course, there are separate “accelerated” drives (used, as a rule, in servers), but they are not omnipotent, and they are also much more expensive to manufacture.
At the same time, in parallel, another direction of information storage systems began to develop, which received the abbreviation SSD (Solid-State Drive), that is, a solid-state (or semiconductor) drive. SSD has a lot of differences from its opponent, the main thing is the absence of the entire mechanical part of the device, instead of which digital systems for writing / reading information are used.
In other words, a solid state drive consists of a controller that controls the operation of memory chips with information, which significantly increases both fault tolerance under physical impact and speed. The first experiments with SSD took place back in 1978, when memory was used similar to operational (volatile), it is able to store information only directly during operation, and then it is completely reset, which, of course, is inconvenient for the storage system.
Much later, with the advent of Flash-memory, that is, non-volatile microcircuits capable of storing information all the time, SSDs began to flourish, and the first manufacturers released new products. Today, many companies are exclusively engaged in the production of SSD devices, most often these are companies that are somehow connected with the production of memory chips, such as Samsung, Micron, Kingston and others. There are also a number of vendors that produce SSDs under their own brand, however, using ready-made products and "semi-finished products" from other manufacturers to assemble their own products.
An SSD consists of digital circuitry and contains no moving parts. The photo above shows the main components of the drive:
- Device memory chips. (usually placed on both sides of the printed circuit board). The volume, reliability and speed of the SSD depends on them.
- Microchip with buffer memory. Developers use different memory chips, but there was no direct dependence on the overall speed of the drive.
- Interface and power connectors. Modern SSDs use the SATA interface in its various versions (SATA-300, SATA-600). SATA is compatible with each other, but the latest versions of this interface allow you to unlock the potential of drives with high speed performance.
- Controller (processor) SSD. The SSD controller is one of the most important parts of the device. It depends on the controller how efficient the SSD will be, whether it will support cleaning technologies and how it is doing with reliability.
Advantages and disadvantagesSSD.
Main advantages:
1) As mentioned earlier, there are no moving parts in the SSD, hence the increased reliability under physical impact. That is, if you drop the hard drive, then it will most likely start to malfunction, or stop working altogether, especially when it comes to impact during operation of the device. A solid state drive is akin to a "flash drive" can withstand light shocks, shocks, vibration.
2) The second and main advantage of SSD is speed. Moreover, many users confuse concepts a bit and believe that high linear read / write speeds of the device (exceeding those on hard drives) are a guarantee of high performance, but this is not entirely true. The main "chip" of the SSD was and remains the high speed of access and response, this is paramount for read operations and it is because of it that files and applications open almost instantly on solid-state drives. While the controller of a traditional HDD is forced to wait for operations performed by the mechanics of the device, the SSD controller is already processing this information by reading it from the memory chips. Moreover, the higher the load (the more different accesses to the logical disk), the greater the advantage will show SSD.
3) The mechanics inside the HDD also affect the power consumption of the device, which is much lower on SSDs.
4) The absence of moving parts affects the noise performance. The SSD does not produce any sounds, at all.
5) "Immunity" to file fragmentation. The HDD loses performance over time due to the fragmentation of recorded files, when they are "scattered" across the platter and the device needs more time to read these files. This is what the defragmentation procedure was invented for. For an SSD, fragmentation is unimportant, as is the location of the file (which again is important for the HDD).
Main disadvantages:
1) Limited number of overwriting information cells. As an example, we can again cite ordinary memory cards, they all have only a limited number of operation cycles, which theoretically reduces the reliability of the device as a whole, in practice this means that the drive will work out its service life during normal use in a home computer / laptop. Developers take into account this feature of the drives, and therefore recommend not to "clog" them completely, leaving free space. However, SSDs often have an additional memory reserve designed just for this. This is necessary for the lifespan of the SSD, as its internal controller tries to avoid any cell getting a critical level of write cycles and constantly works to increase the lifespan of the device by choosing the least worn out cells.
2) Price for 1 GB. In terms of price per 1 GB of information, SSDs are still losing to their "brothers" hard drives, but considering that every year, the volume of devices is growing, and prices are constantly decreasing, we can safely say that sooner or later solid-state memory will equal its prices. characteristics with hard drives (or replace it completely).
3) human factor. To work with SSD, it is desirable to follow a few simple rules. If they are neglected, then the device can “grow old” faster than the time allotted to it, which will affect the decrease in speed, and subsequently on the fault tolerance of the SSD.
SSD orHDD?
SSDs are evolving at an insane pace. Controllers and memory chips are constantly improving, production volumes are increasing, and even corporations are already switching to using solid state drives. The question of "what to choose now" is quite simple: ? But the time will soon come when HDDs, to one degree or another, will begin to lose ground on the market, as it is happening, in fact, already now. And in the end, this question will disappear by itself. Think about it, not so long ago, everyone had CRT monitors on their desks, and people were arguing about expensive and inferior LCD devices. Similarly, we went to buy film for cameras. But will you find new models of CRT monitors in the store now, or maybe you will get something other than a digital camera for shooting vacations?
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First SSD, or solid state drives using flash memory, appeared in 1995, and were used exclusively in the military and aerospace fields. The huge cost at that time was compensated by the unique characteristics that allow the operation of such disks in aggressive environments over a wide temperature range.
In the mass market, drives SSD appeared not so long ago, but quickly became popular, as they are a modern alternative to a standard hard drive ( HDD ). Let's figure out what parameters you need to choose a solid state drive, and what it is all about.
Device
Out of habit SSD is called a "disk", but it could rather be called " solid box”, since there are no moving parts in it, and nothing similar in shape to a disk either. The memory in it is based on the physical properties of the conductivity of semiconductors, so that SSD- a semiconductor (or solid state) device, while a conventional hard disk can be called an electro-mechanical device.
Abbreviation SSD just means " solid state drive ", that is, literally, " solid state drive". It consists of a controller and memory chips.
Controller- the most important part of the device that connects the memory with the computer. Main characteristics SSD- the data exchange rate, power consumption, etc., depend on it. The controller has its own microprocessor, running according to a preset program, and can perform the functions of correcting code errors, preventing wear, and cleaning debris.
Memory in drives can be either non-volatile ( NAND), and energy-dependent ( RAM).
NAND memory won at first HDD only in the speed of access to arbitrary memory blocks, and only since 2012, the read / write speed has also increased many times over. Now in the mass market drives SSD are represented by models with non-volatile NAND-memory.
RAM The memory is characterized by ultra-fast read and write speeds, and is built on the principles of computer RAM. Such memory is volatile - in the absence of power, the data disappears. It is usually used in specific areas, such as speeding up work with databases, it is difficult to find it on sale.
Differences between SSD and HDD
SSD distinguishes from HDD First of all, the physical device. Thanks to this, it boasts some advantages, but it also has a number of serious disadvantages.
Main advantages:
· Speed. Even from the technical specifications, it can be seen that the read / write speed of SSD several times higher, but in practice the performance can vary by 50-100 times.
· No moving parts and therefore no noise. It also means high mechanical resistance.
· The speed of random access to memory is much higher. As a result, the speed of work does not depend on the location of the files and their fragmentation.
· Much less vulnerable to electromagnetic fields.
· Small size and weight, low power consumption.
Flaws:
· Resource limitation by rewriting cycles. It means that you can overwrite a single cell a certain number of times - on average, this figure varies from 1,000 to 100,000 times.
The cost of a gigabyte of volume is still quite high, and exceeds the cost of a regular HDD several times. However, this shortcoming will disappear with time.
Difficulty or even impossibility of recovering deleted or lost data associated with the hardware command used by the drive TRIM, and with high sensitivity to power supply voltage drops: with such damage to memory chips, information from them is irretrievably lost.
In general, solid state drives have a number of advantages that standard hard drives do not have - in cases where speed, access speed, size and resistance to mechanical stress play a major role, SDD pushes hard HDD.
How much SSD will you need?
The first thing you should pay attention to when choosing SSD- its volume. On sale there are models with a capacity of 32 to 2000 GB.The solution depends on the use case - you can install only the operating system on the drive, and limit yourself to the volume SSD in 60-128 GB, which will be sufficient for Windows and installation of basic programs.
The second option is to use SSD as the main media library, but then you need a disk with a capacity of 500-1000 GB which will be quite expensive. This only makes sense if you're working with a lot of files that need to be accessed really quickly. With regard to the average user - not a very rational price / speed ratio.
But there is another property of solid-state drives - depending on the volume, the write speed can vary greatly. The larger the disk capacity, the higher the write speed, as a rule. This is due to the fact that SSD is able to use several memory crystals in parallel at once, and the number of crystals grows along with the volume. That is, in the same models SSD with different capacities of 128 and 480 GB, the difference in speed can vary by about 3 times.
Given this feature, we can say that now the most optimal choice in terms of price / speed can be called 120-240 GB SSD models, they will be enough to install the system and the most important software, and maybe for several games.
Interface and form factor
2.5" SSD
The most common form factor SSD is a 2.5 inch format. It is a “bar” with dimensions of approximately 100x70x7mm, they may vary slightly from different manufacturers (± 1mm). The interface of 2.5" drives is usually SATA3(6 Gbps).Advantages of the 2.5" format:
- Prevalence in the market, any volume is available
- Convenient and easy to use, compatible with any motherboard
- Democratic price
- Relatively low speed among ssds - up to a maximum of 600 Mb / s per channel, against, for example, 1 Gb / s for a PCIe interface
- AHCI controllers that were designed for classic hard drives
mSATA SSD
There is a more compact form factor - mSATA, sizes 30x51x4 mm. It makes sense to use it in laptops and any other compact devices where the installation of a conventional 2.5” drive is impractical. If they have a connector of course mSATA. In terms of speed, it's still the same specification. SATA3(6 Gbps), and does not differ from 2.5".
M.2 SSD
There is another, the most compact form factor M.2, gradually changing mSATA. Designed mainly for laptops. Dimensions - 3.5x22x42 (60.80) mm. There are three different bar lengths - 42, 60 and 80mm, pay attention to compatibility when installing in your system. Modern motherboards offer at least one U.2 M.2 slot.M.2 can be either SATA or PCIe. The difference between these interface options is in speed, and quite a big one at that - SATA drives can boast an average speed of 550 Mb / s, while PCIe, depending on the generation, can offer 500 Mb / s per lane for PCI-E 2.0. and speeds up to 985 Mb/s per PCI-E 3.0 lane. Thus, an SSD installed in a PCIe x4 slot (with four lanes) can exchange data at speeds up to 2 Gb / s in the case of PCI Express 2.0 and up to almost 4 Gb / s when using PCI Express third generation.
At the same time, the differences in price are significant, an M.2 form factor drive with a PCIe interface will cost, on average, twice as much as a SATA interface with the same volume.
The form factor has a U.2 connector, which may have connectors that differ from each other keys- special "cutouts" in them. There are keys B and , and also B&M. Different bus speeds PCIe: key M provide speed up to PCIe x4, key M speed up to PCIe x2, like the combined key B&M.
B- the connector is not compatible with M- connector, M-connector, respectively, with B- connector, and B&M connector is compatible with any. Be careful when purchasing M.2, since the motherboard, laptop or tablet must have a suitable connector.
PCI-e SSD
Finally, the last existing form factor - as an expansion board PCI-E. Mounted, respectively, in the slot PCI-E, have the highest speed, of the order 2000 MB/s read and 1000 MB/s write. Such speeds will cost you very dearly: it is obvious that choosing such a drive is worth it for professional tasks. 
NVM Express
There are also SSD, having a new logical interface NVM Express, designed specifically for solid state drives. It differs from the old AHCI by even lower access latencies and high parallelism of memory chips due to a new set of hardware algorithms.There are models on the market both with a connector M.2, as well as in PCIe. The downside of PCIe here is that it will take up an important slot, which can be useful for another board.
Since the standard NVMe designed specifically for flash memory, it takes into account its features, while AHCI Still, it's just a compromise. That's why, NVMe is the future of SSDs and will only get better over time.
What type of memory is best in an SSD?
Understanding the types of memory SSD. This is one of the main characteristics SSD, determining cell rewriting resource and speed.MLC (Multi Level Cell)- the most popular type of memory. Cells contain 2 bits, unlike the 1st bit in the old type SLC which is almost out of stock. This results in a larger volume, which means a lower cost. Recording resource from 2000 to 5000 rewriting cycles. In this case, "overwriting" means overwriting each cell of the disk. Therefore, for a 240 GB model, for example, you can record at least 480 TB of information. So, such a resource SSD even with constant intensive use, 5-10 years of commercials should be enough (for which it will still be very outdated). And for home use, it will last for 20 years at all, so the limited rewriting cycles can be completely ignored. MLC- this is the best combination of reliability / price.
TLC (Triple Level Cell)- it follows from the name that 3 bits of data are stored in one cell at once. The recording density here is compared to MLC higher by whole 50% , which means that the rewriting resource is less - only from 1000 cycles. Access speed is also lower due to higher density. The price is not much different now. MLC. It has long been widely used in flash drives. The service life is also sufficient for a home solution, but the susceptibility to uncorrectable errors and the "death" of memory cells is noticeably higher, and during the entire service life.
3D NAND- it is more a form of memory organization, and not its new type. Exists like MLC, and TLC 3D NAND. Such a memory has vertically placed memory cells, and a separate memory chip in it has several levels of cells. It turns out that the cell has a third spatial coordinate, hence the prefix "3D" in the name of the memory - 3D NAND. It features a very low error rate and high endurance due to the larger process technology of 30-40nM.
The manufacturer's warranty for some models reaches 10 years of use, but the cost is high. The most reliable type of memory in existence.
Differences between cheap SSDs and expensive ones
Disks of the same volume can differ greatly in price even from the same manufacturer. A cheap SSD can differ from an expensive one in the following ways:· Cheaper type of memory. In ascending order of cost / reliability, conditionally: TLC≥ MLC ≥ 3D NAND.
· Cheaper controller. Also affects read/write speed.
· Clipboard. The cheapest SSDs may not have a clipboard at all, this does not make them much cheaper, but it significantly reduces performance.
· Protection systems. For example, expensive models have power interruption protection in the form of reserve capacitors, which allow you to correctly complete the write operation and not lose data.
· Brand. Of course, a more popular brand will be more expensive, which does not always mean technical superiority.
Conclusion. What is more profitable to buy?
It is safe to say that modern SSD drives are quite reliable. The fear of data loss and the negative attitude towards solid state drives as a class are completely unjustified at the moment. If we talk about more or less popular brands, then even a cheap TLC memory is suitable for budget home use, and its resource will last you for several years at least. Many manufacturers also offer a 3-year warranty.So, if you are limited in funds, then your choice is a capacity of 60-128 GB to install the system and frequently used applications. The type of memory is not so critical for home use - TLC it will be or MLC, the disk will become obsolete before the resource is exhausted. Other things being equal, of course, it is worth choosing MLC.
If you are ready to look into the middle price segment and value reliability, then it is better to consider MLC SSD 200-500 GB. For older models, you will have to pay about 12 thousand rubles. At the same time, the volume will be enough for you for almost everything that should work quickly on a home PC. You can also take models of even more increased reliability with memory crystals 3D NAND .
If your fear of flash memory wear and tear reaches panic levels, then it's worth looking at new (and expensive) technologies in the form of storage formats. 3D NAND. And if no jokes, then this is the future SSD– high speed and high reliability are combined here. Such a drive is suitable even for important server databases, since the write resource here reaches petabyte, and the number of errors is minimal.
In a separate group, I would like to allocate drives with an interface PCI-E. It has high read and write speed 1000-2000 Mbps), and on average more expensive than other categories. If speed is the top priority, then this is the best choice. The disadvantage is that it occupies a universal PCIe slot; motherboards of compact formats can have only one PCIe slot.
Out of competition - SSD with NVMe logical interface, the reading speed of which exceeds 2000 Mb / s. Compared to SSD compromise logic AHCI, has much greater queue depth and concurrency. High cost on the market, and the best performance - the choice of enthusiasts or professionals.
More and more users are purchasing SSD drives for installation in a PC. They are used in parallel with or instead of the HDD. Most often, the operating system is installed on the SSD drive, and files are stored on the HDD. It is with this placement that you can experience a multiple increase in the speed and performance of your computer.
Solid state drives have many advantages over hard drives. Therefore, you need to know how to choose the right SSD drive for your computer.
What does it represent?
A hard disk drive (HDD) is that device in your computer that stores all data (programs, movies, images, music ... the Windows operating system itself, Mac OS, Linux, etc.) and it looks like this ...
Information on the hard drive is written (and read) by reversing the cells on magnetic plates that rotate at a wild speed. Above the plates (and between them) is worn, like a frightened, special carriage with a reading head.
Since the HDD is in constant rotation, it works with a certain noise (buzzing, crackling), this is especially noticeable when copying large files and starting programs and the system, when the hard drive is under maximum load. In addition, this is a very "thin" device and is afraid of even a simple wobble during its operation, not to mention falling to the floor, for example (reading heads will meet with rotating disks, which will lead to the loss of stored information on the disk).
Now consider a solid state drive (SSD). This is the same information storage device, but based not on rotating magnetic disks, but on memory chips, as mentioned above. The device is similar to a large flash drive.
Nothing spinning, moving and buzzing - the SSD drive is absolutely silent! Plus - just a crazy speed of writing and reading data!
Advantages and disadvantages
Advantages:
- high speed of reading and writing data and performance;
- low heat generation and power consumption;
- no noise due to the absence of moving parts;
- small dimensions;
- high resistance to mechanical damage (overloads up to 1500g), magnetic fields, temperature extremes;
- stability of data reading time irrespective of memory fragmentation.
Flaws:
- limited number of rewriting cycles (1,000 - 100,000 times);
- high price;
- exposure to electrical damage;
- the risk of complete loss of information without the possibility of its recovery.
And now in more detail:
Benefits of an SSD drive
1. Work speed
This is the most important advantage of SSD drives! After replacing the old hard drive with a flash drive, the computer acquires multiple acceleration due to the high speed of data transfer.
Before the advent of SSD drives, the hard drive was the slowest device in a computer. It, with its ancient technology from the last century, incredibly slowed down the enthusiasm for a fast processor and nimble RAM.
2. Noise level=0 dB
Logically - there are no moving parts. In addition, these drives do not get hot during their operation, so the cooling coolers turn on less often and work less intensively (creating noise).
3. Shock and vibration resistance
This is confirmed by numerous videos with tests of these devices - the connected and working SSD was shaken, dropped to the floor, knocked on it ... and it continued to work quietly! If you are purchasing an SSD drive for yourself, and not for testing, we advise you not to repeat these experiments, but limit yourself to watching videos on Youtube.
4. Light weight
Not an outstanding factor, of course, but still - hard drives are heavier than their modern competitors.
5. Low power consumption
I'll dispense with the numbers - the battery life of my old laptop has increased by more than one hour.
Disadvantages of an SSD drive
1. High cost
This is at the same time the most deterrent for users, but it is also very temporary - the prices for such drives are constantly and rapidly falling.
2. Limited number of overwrite cycles
A typical, average SSD based on flash memory with MLC technology is capable of approximately 10,000 read / write cycles of information. But the more expensive type of SLC memory can already live 10 times longer (100,000 rewrite cycles).
In both cases, the flash drive can easily work out for at least 3 years! This is just the average life cycle of a home computer, after which there is a configuration update, replacement of components with more modern ones.
Progress does not stand still and tadpoles from manufacturing companies have already come up with new technologies that significantly increase the lifetime of SSD drives. For example, RAM SSD or FRAM technology, where the resource, although limited, is practically unattainable in real life (up to 40 years in continuous read / write mode).
3. The impossibility of recovering deleted information
No special utility can recover deleted information from an SSD drive. Such programs simply do not exist.
If, with a large power surge in a regular hard drive, only the controller burns out in 80% of cases, then in SSD drives this controller is located on the board itself, along with memory chips, and the entire drive burns out - hello to the family photo album.
This danger is practically reduced to zero in laptops and when using an uninterruptible power supply.
Main characteristics
If you are buying an SSD to install on a computer, pay attention to its main characteristics.
Volume
When buying an SSD drive, first of all, pay attention to the volume and purpose of use. If you are purchasing it only for OS installation, choose a device with at least 60 GB of memory.
Today's gamers prefer to install games on solid state drives in order to increase performance. If you are one of them, then you need a 120 GB variant.
If you're purchasing an SSD instead of a hard drive, consider how much information is stored on your computer. But in this case, the capacity of the SSD disk should not be less than 250 GB.
Important! The cost of a solid state drive directly depends on the volume. Therefore, if your budget is limited, use an SSD to install the operating system, and an HDD for data storage.
Form factor
Most modern models of SSD drives are sold in a 2.5-inch form factor and are built into a protective box. Because of this, they look like classic hard drives of the same size.
Good to know! To install a 2.5-inch SSD drive in a standard 3.5-inch mount inside the PC case, special adapters are used. Some case models have 2.5-inch form factor jacks.
There are 1.8-inch and smaller SSDs on the market that are used in compact devices.
Connection interface
Solid state drives have several options for connection interfaces:
- SATA II;
- SATA III;
- PCIe;
- mSATA;
- PCIe+M.2.
The most common option is to connect using a SATA connector. There are still SATA II models on the market. They are no longer relevant, but even if you purchase such a device, due to the backward compatibility of the SATA interface, it will work with a motherboard that supports SATA III.
When using a PCIe SSD, you may need to install drivers, but the data transfer speed will be higher than with a SATA connection. But there are not always drivers for Mac OS, Linux and the like - you should pay attention to this when choosing.
mSATA models are used on compact devices, but work on the same principle as the standard SATA interface.
The M.2 or NGFF (Next Generation Form Factor) models are a continuation of the development of the mSATA line. They have smaller dimensions and greater layout possibilities for digital equipment manufacturers.
Read/write speed
The higher this value, the more productive the computer. Average speed indicators:
- reading 450-550 Mb/s;
- recording 350-550 Mb/s.
Manufacturers may indicate not the actual, but the maximum read / write speed. To find out the real numbers, look on the Internet for reviews and reviews of the model you are interested in.
In addition, pay attention to the access time. This is the time it takes the disk to find the information required by the program or OS. The standard indicator is 10-19 ms. But since SSDs have no moving parts, they are significantly faster than HDDs.
Memory type and time to failure
There are several types of memory cells used in SSD drives:
- MLC (Multi Level Cell);
- SLC (Single Level Cell);
- TLC (Three Level Cell);
- 3D V-NAND.
MLC is the most common type, which allows you to store two bits of information in one cell. It has a relatively small resource of rewrite cycles (3,000 - 5,000), but a lower cost, due to which this type of cells is used for mass production of solid state drives.
The SLC type stores only one bit of data per cell. These microcircuits are characterized by long lifetime (up to 100,000 write cycles), high data transfer rate, and minimal access time. But due to the high cost and small amount of data storage, they are used for server and industrial solutions.
The TLC type stores three bits of data. The main advantage is the low cost of production. Among the disadvantages: the number of rewriting cycles is 1,000 - 5,000 repetitions, and the read / write speed is significantly lower than the first two types of microcircuits.
Healthy! Recently, manufacturers have managed to increase the lifetime of TLC disks up to 3,000 rewriting cycles.
3D V-NAND models use 32-layer flash memory instead of standard MLC or TLC chips. The microchip has a three-dimensional structure, due to which the amount of recorded data per unit area is much higher. This increases the reliability of information storage by 2-10 times.
IOPS
An important factor is IOPS (the number of input / output operations per second), the higher this indicator, the faster the drive will work with a large amount of files.
memory chip
Memory chips are divided into two main types MLC and SLC. The cost of SLC chips is much higher and the service life is on average 10 times longer than that of MLC memory chips, but with proper operation, the service life of drives based on MLC memory chips is at least 3 years.
Controller
This is the most important part of SSD drives. The controller manages the operation of the entire drive, distributes data, monitors the wear of memory cells and evenly distributes the load. I recommend giving preference to time-tested and well-proven controllers from SandForce, Intel, Indilinx, Marvell.
SSD memory capacity
It will be most practical to use an SSD only to host the operating system, and it is better to store all data (movies, music, etc.) on a second hard drive. With this option, it is enough to buy a disk with a size of ~ 60 GB. Thus, you can save a lot and get the same acceleration of your computer (in addition, the life of the drive will increase).
Again, I will give my solution as an example - special containers for hard drives are sold on the network (very inexpensively), which are inserted into a laptop in 2 minutes instead of an optical CD drive (which I used a couple of times in four years). Here's a great solution for you - the old disk in place of the drive, and the brand new SSD in place of the regular hard drive. It couldn't have been better.
And finally, a couple of interesting facts:
Why is a hard drive often called a hard drive? Back in the early 1960s, IBM released one of the first hard drives and the number of this development was 30 - 30, which coincided with the designation of the popular rifled weapon Winchester (Winchester), so such a slang name has taken root to all hard drives.
Why exactly hard disk? The main elements of these devices are several round aluminum or non-crystalline glassy plates. Unlike floppy disks (floppy disks), they cannot be bent, so they called it a hard disk.
TRIM function
The most important additional feature for a solid state drive is TRIM (garbage collection). It is as follows.
Information on the SSD is first written to free cells. If the disk writes data to a cell that was previously used, it first clears it (unlike the HDD, where data is written over the existing information). If the model does not support TRIM, it clears the cell just before writing new information, which slows down this operation.
If the SSD supports TRIM, it receives a command from the OS to delete the data in the cell and clears them not before overwriting, but during the “idle” of the disk. This is done in the background. This keeps the write speed at the level specified by the manufacturer.
Important! The TRIM feature must be supported by the operating system.
hidden area
This area is not accessible to the user and is used to replace failed cells. In high-quality solid-state drives, it is up to 30% of the volume of the device. But some manufacturers, in order to reduce the cost of an SSD drive, reduce it by up to 10%, thereby increasing the amount of storage available to the user.
The flip side of this trick is that the hidden area is used by the TRIM function. If its volume is small, it will not be enough for background data transfer, which is why at an SSD “load” level of 80-90%, the write speed will drop sharply.
Bus bandwidth
So, when choosing a flash drive, the speed of reading and writing data is also of paramount importance. The higher this speed, the better. But you should also remember about the bus bandwidth of your computer, or rather, the motherboard.
If your laptop or desktop computer is very old, there is no point in buying an expensive and fast SSD drive. He just won't be able to work even at half his capacity.
To make it clearer, I will announce the bandwidth of various buses (data transfer interface):
IDE (PATA) - 1000 Mbps. This is a very ancient interface for connecting devices to the motherboard. To connect an SSD drive to such a bus, you need a special adapter. The meaning of using the described disks in this case is absolute zero.
SATA - 1500 Mbit/s. More fun, but not too much.
SATA2 - 3000 Mbit/s. The most common tire at the moment. With such a bus, for example, my drive works at half its capacity. He needs...
SATA3 - 6000 Mbit/s. This is a completely different matter! This is where the SSD drive will show itself in all its glory.
So, before buying, find out what kind of bus you have on the motherboard, as well as which one the drive itself supports, and make a decision on the appropriateness of the purchase.
Here, for example, how I chose (and what guided me) my HyperX 3K 120 GB. The read speed is 555 MB/s and the data write speed is 510 MB/s. This drive in my laptop now works at exactly half its capabilities (SATA2), but exactly twice as fast as a regular hard drive.
Over time, he will migrate to the children's gaming computer, where there is SATA3, and he will demonstrate there all his power and all the speed of work without constraining factors (outdated, slow data transfer interfaces).
We conclude: if you have a SATA2 bus in your computer and you do not plan to use the disk in another (more powerful and modern) computer, buy a disk with a bandwidth of no more than 300 MB / s, which will be significantly cheaper and at the same time twice as fast as yours. current hard drive.
In recent years, SSD drives have become increasingly available and cheaper. However, while they still remain more expensive than traditional HDD hard drives. So, what is an SSD, what are the advantages of using it, how will working with an SSD differ from an HDD?
What is a solid state hard drive?
In general, the technology of solid-state hard drives is quite old. SSDs have been on the market in various forms for decades. The very first of these were based on RAM memory and were used only in the most expensive corporate and super-computers. In the 1990s, SSDs based on flash memory appeared, but their price did not allow them to enter the consumer market, so these drives were familiar mainly to computer scientists in the United States. During the 2000s, the price of flash memory continued to fall, and by the end of the decade, SSDs began to appear in mainstream personal computers.
Intel Solid State Drive
What exactly is an SSD drive? First, what is a regular hard drive. HDD is, simply put, a set of metal disks covered with a ferromagnet that rotate on a spindle. Information can be written to the magnetized surface of these discs using a small mechanical head. Data is stored by reversing the polarity of the magnetic elements on the disks. Actually, things are a little more complicated, but this should be enough to understand that writing and reading to hard drives is not very different from playing records. When you need to write something to the HDD, the discs rotate, the head moves to find the right location, and the data is written or read.
In contrast, SSD hard drives have no moving parts. Thus, they are more similar to the well-known flash drives than to ordinary hard drives or record players. Most SSD drives use NAND for storage, a type of non-volatile memory that does not require electricity to store data (unlike RAM on your computer, for example). NAND memory, among other things, provides a significant increase in speed compared to mechanical hard drives, if only because it does not take time to move the head and rotate the disk.
Comparison of SSD and conventional hard drives
So, now that we have a little bit of what SSDs are, it would be nice to know how they are better or worse than regular hard drives. Here are a few key differences.
Spindle Spin Time: This feature exists for hard drives - for example, when you wake up your computer from sleep, you may hear a click and spin up sound that lasts for a second or two. There is no spin-up time on an SSD.
Data access time and latency: in this regard, the speed of SSD differs from conventional hard drives by about 100 times, not in favor of the latter. Due to the fact that the stage of mechanically searching for the right places on the disk and reading them is skipped, access to data on the SSD is almost instantaneous.
Noise: SSDs do not make sounds. You probably know how a regular hard drive can make noise.
Reliability: the failure of the vast majority of hard drives are the result of mechanical damage. At some point, after several thousand hours of use, the mechanical parts of the hard drive simply wear out. At the same time, if we talk about the lifetime, hard drives win, and there are no restrictions on the number of rewrite cycles in them.
In turn, solid-state drives have a limited number of write cycles. Most critics of SSD most often note this factor. In reality, it will not be easy for a normal user to reach these limits during normal use of a computer. SSD hard drives are commercially available with 3 and 5 year warranties, which they tend to outlast, and sudden SSD failure is the exception rather than the rule, it just makes more noise for some reason. For example, we are 30-40 times more likely to come to our workshop with damaged HDDs, and not SSDs. Moreover, if the failure of the hard drive is sudden and means that it is time to look for someone who will get data from it, then with an SSD it happens a little differently and you will know in advance that it will need to be changed soon - it is "gets old" and does not die abruptly, some blocks become read-only, and the system warns you about the state of the SSD.
Power Consumption: SSDs consume 40-60% less power than regular HDDs. This allows, for example, to significantly increase the battery life of a laptop when using an SSD.
Price: SSDs cost more than conventional hard drives per gigabyte. However, they have become much cheaper than 3-4 years ago and are already quite affordable. The average price of SSD drives hovered around $1 per gigabyte (August 2013).
Working with an SSD
As a user, the only difference you will notice when working on the computer, using the operating system, running programs, is a significant increase in speed. However, when it comes to extending the life of an SSD, there are a few important rules you need to follow.
Don't defragSSD. Defragmentation is completely useless for a solid state drive and reduces its life. Defragmentation is a way to physically transfer to one place fragments of files located in different parts of the hard drive, which reduces the time required for mechanical actions to search for them. In solid-state drives, this is irrelevant, since they do not have moving parts, and the search time for information on them tends to zero. By default, in Windows 7 defragmentation for SSDs is disabled.
Disable Indexing Services. If your operating system uses any file indexing service for faster file retrieval (Windows does), disable it. The speed of reading and searching for information is sufficient to do without an index file.
Your operating system must supportTRIM. The TRIM command allows the operating system to communicate with your SSD and tell it which blocks are no longer in use and can be cleared. Without the support of this command, the performance of your SSD will degrade rapidly. TRIM is currently supported on Windows 7, Windows 8, Mac OS X 10.6.6 and higher, and Linux kernel 2.6.33 and higher. Windows XP does not support TRIM, although there are ways to implement it. In any case, it is better to use a modern operating system with an SSD.
Don't need to fillFull SSD. Read the specifications for your solid state drive. Most manufacturers recommend leaving 10-20% of its capacity free. This free space must be left to use utility algorithms that extend the life of the SSD by spreading data in NAND memory for even wear and higher performance.
Store data on a separate hard drive. Despite the decline in the price of SSDs, it makes no sense to store media files and other data on an SSD. Things like movies, music or pictures are better stored on a separate hard drive, these files do not require high access speeds, and the HDD is still cheaper. This will extend the life of the SSD.
Install more RAMram. Today, RAM memory is very cheap. The more RAM installed on your computer, the less often the operating system will turn to the SSD for a paging file. This significantly extends the life of the SSD.
Do you need an SSD drive?
You decide. If most of the items listed below suit you and you are ready to shell out several thousand rubles, then take the money to the store:
- You want your computer to turn on in seconds. When using an SSD, the time from pressing the power button to opening a browser window is minimal, even if there are third-party programs in startup.
- You want games and programs to launch faster. With an SSD, when you launch Photoshop, you don’t have time to see its authors on the splash screen, and the speed of loading maps in large-scale games increases by 10 or more times.
- You want a quieter and less power hungry computer.
- You are willing to pay more per megabyte, but get a higher speed. Despite the reduction in the price of SSDs, they are still many times more expensive than conventional hard drives in terms of gigabytes.
If most of the above is about you, then go for the SSD!
