What are information carriers. Electronic storage media - what is it? Hard Disk Drives

Information carriers are distributed according to four parameters: the nature of the carrier, its purpose, the number of write cycles and durability.

By nature, information carriers are material-objective and biochemical. The first ones are those that can be touched, picked up, moved from place to place: letters, books, flash drives, disks, finds of archaeologists and paleontologists. The latter are biological in nature and cannot be physically touched: the genome, any part of it - RNA, DNA, genes, chromosomes.

According to the purpose, information carriers are divided into specialized and general purpose. Specialized - these are those that are created for only one type of information storage. For example, for digital recording. And a broad purpose is a medium on which information can be written in different ways: the same paper, they write and draw on it.

According to the number of recording cycles, the media can be single or multiple. On the first one, you can write information only once, on the second - a lot. An example of a one-time information carrier is a CD-R disc, and a CD-RW disc is already a multiple one.

The durability of the media is the period that it will store information. Those that are considered short-lived inevitably collapse: if you write something on the sand near the water, the wave will wash away the inscription in half an hour or an hour. And long-term ones can only be destroyed by a random circumstance - a library will burn down or a flash drive will suddenly fall into the sewer and lie in the water for many years.

They make storage media from four types of material:

• paper, from which punched cards and punched tapes used to be made, and book pages are still being made;
• plastic for optical discs or tags;
• magnetic materials needed for magnetic tapes;
• semiconductors that are used to create computer memory.

In the past, the list was richer: information carriers were made from wax, fabric, birch bark, clay, stone, bone, and much more.

To change the structure of the material from which the information carrier is created, 4 types of influences are used:

• mechanical - sewing, carving, drilling;
• electrical - electrical signals;
• thermal - burning out;
• chemical - etching or staining.

Of the media of the past, punched cards and punched tapes, magnetic tapes, and then 3.5-inch floppy disks were the most popular.

Punched cards were made of cardboard, then they were pierced in the right places so that the holes in the cardboard resembled a pattern, and information was read from them. And punched tapes appeared later, were paper and were used in the telegraph.

Magnetic tapes reduced the popularity of punched cards and punched tapes to zero. Such tapes could both store and reproduce information - play recorded songs, for example. At the same time, tape recorders appeared on which it was possible to listen to both cassettes and reels. But the shelf life of magnetic tapes was modest - up to 50 years.

When floppy disks appeared, magnetic tapes became a thing of the past. Floppy disks were small, 3.5 inches, and could store up to 3 MB of information. However, they were sensitive to magnetic influences, and their capacity could not keep up with the needs of people - they needed media that could store much more data.

Now there are many such media: external hard drives, optical drives, flash drives, HDD boxes and remote servers.

external HDs

External hard drives are packaged in a compact case with one or two USB adapters and anti-vibration system. They can store up to 2 TB of information.

• easy to connect: no need to turn off the computer, mess with the power cable and sata - external hard drives have a USB0 interface, they are connected like regular flash drives;
• easy to transport: such devices are very small, they can easily be taken on a trip, on a visit, you can even carry them in your pocket, and also, they are quite easy to connect to a home theater;
• You can connect as many hard drives to your computer as there are USB ports.

• the information transfer rate is lower than over a sata connection;
• need increased power supply, so double USB cable is required;
• The case is plastic, which means that during operation you can hear clicks or other noise.

However, if the disk is in a rubberized metal case, then no one will hear the noise.

External hard drives are portable (2.5) and desktop (3.5). The interface can be exotic - firewire or bluetooth, but these are more expensive, they are less common and they need an additional power supply.

Optical discs

These are CDs, LaserDiscs, HD-DVDs, MiniDisks and Blu-ray. Information from such discs is read using optical radiation, which is why they are called so.

The optical disc has four generations:

• the first is laser, compact and mini-disc;
• the second - DVD and CD-ROM;
• third - HD-DVD and Blu-ray;
• fourth - Holographic Versatile Disc and SuperRens Disc.

CDs are almost never used anymore. They have a small volume - 700 MB, and the data from them is read by a laser beam. Compact discs were divided into two types: those on which nothing could be written (CD), and those on which it was possible to record (CD-R and CD-RW).

DVDs look the same as CDs, but they are much larger. DVDs come in several formats, the most popular being 4.37 GB DVD-5 and 7.95 GB DVD-9. Such discs are also R - for one-time recording, and RW - for multiple recordings.

Blu-ray discs, being the same size as CDs and DVDs, can store much more data - up to 25 and up to 50 GB. Up to 25 are discs with one information recording layer, and up to 50 are with two. And they are also subdivided into R - single entry, and RE - multiple entry.

Flash drives

A flash drive is a very small device that can store up to 64 GB or more. Flash drives are connected to the computer via a USB port, they have a high read and write speed, the case is plastic. Inside the flash drive is an electronic board with a memory chip.

A flash drive can be connected to a computer and TV, and if it is in Micro-cd format, then to a tablet or smartphone. Scratches and dust that could destroy optical discs are not terrible for a flash drive - it has a slight susceptibility to external influences.

HDD boxes

This is an option that allows you to use ordinary desktop hard drives as external ones. HDD box is a plastic box with a USB controller, where you can put a regular hard drive and easily transfer information directly, avoiding additional copy and paste.

An HDD box is much cheaper than an external hard drive, and is very useful if you need to transfer a large amount of information or even almost the entire hard drive partition to another computer.

Remote servers

This is a virtual way of storing data. The information will be on a remote server, which can be connected to from a computer, from a tablet, and from a smartphone, you just need to have access to the Internet.

With physical storage media, there is always a risk of losing data because a flash drive, hard drive or optical drive can break. But there is no such problem with a remote server - the information is stored securely and for as long as the user needs. In addition, remote servers have backup storage in case of unforeseen situations.

Information carrier- the physical environment directly storing information. The main carrier of information for a person is his own biological memory (human brain). A person's own memory can be called working memory. Here the word "operational" is synonymous with the word "fast". Learned knowledge is reproduced by a person instantly. We can also call our own memory internal memory, since its carrier - the brain - is inside us.

Information carrier- a strictly defined part of a particular information system, which serves for intermediate storage or transmission of information.

The basis of modern information technology is the computer. When it comes to computers, we can talk about storage media as external storage devices (external memory). These data carriers can be classified according to various features, for example, according to the type of execution, the material from which the carrier is made, etc. Here is one of the options for classifying media:

Tape media

Magnetic tape- a magnetic recording medium, which is a thin flexible tape consisting of a base and a magnetic working layer. The working properties of a magnetic tape are characterized by its sensitivity during recording and signal distortion during recording and playback. The most widely used is a multilayer magnetic tape with a working layer of needle-shaped particles of magnetically hard powders of gamma-iron oxide (y-Fe2O3), chromium dioxide (CrO2) and gamma-iron oxide modified with cobalt, usually oriented in the direction of magnetization during recording.

Disk media refer to machine media with direct access. The concept of direct access means that the PC can “access” the track on which the section with the required information begins or where new information needs to be written.

Disk drives are the most diverse:

Floppy disk drives (FPHD), they are also floppy disks, they are also floppy disks

Hard disk drives (HDD), they are also hard drives (popularly just "screws")

Optical CD drives:

• CD-ROM (Compact Disk ROM)

In floppy disk drives (NGMD or floppy disks) and hard disk drives (HDD or hard drives), the basis for recording, storing and reading information is the magnetic principle, and in laser disk drives - the optical principle.

Flexible magnetic disks placed in a plastic case. This storage medium is called a floppy disk. A floppy disk is inserted into a disk drive that rotates the disk at a constant angular velocity. The magnetic head of the drive is installed on a certain concentric track of the disk, on which information is written (or read).

The information capacity of a floppy disk is small and amounts to only 1.44 MB. The speed of writing and reading information is also low (about 50 KB / s) due to the slow rotation of the disk (360 rpm).

Hard magnetic disks.

Hard disk (HDD - Hard Disk Drive) refers to non-replaceable disk magnetic drives. The first hard drive was developed by IBM in 1973 and had a capacity of 16 KB. Hard magnetic disks are several tens of disks placed on the same axis, enclosed in a metal case and rotating at a high angular velocity. The speed of writing and reading information from hard disks is quite high (about 133 MB / s) due to the fast rotation of disks (7200 rpm).

Failures occur during the operation of the computer. Viruses, power outages, software errors - all this can cause damage to the information stored on your hard drive. Damage to information does not always mean loss of it, so it is useful to know how it is stored on the hard drive, because then it can be restored. Then, for example, if the boot area is damaged by a virus, it is not at all necessary to format the entire disk (!), but, after restoring the damaged area, continue normal work with the preservation of all your priceless data.

Hard disks use rather fragile and miniature elements. To preserve the information and performance of hard drives, it is necessary to protect them from shocks and sudden changes in spatial orientation during operation.

Laser drives and disks.

In the early 80s, the Dutch company Philips announced a revolution in the field of sound reproduction. Its engineers came up with something that is now very popular - These are laser discs and players.

Laser disk drives use the optical principle of reading information. On CD (CD - Compact Disk, compact disc) and DVD (DVD - Digital Video Disk, digital video disc) laser discs, information is recorded on one spiral track (like on a gramophone record) containing alternating sections with different reflectivity. The laser beam falls on the surface of a rotating disk, and the intensity of the reflected beam depends on the reflectivity of the track section and acquires the values ​​0 or 1. To preserve information, laser disks must be protected from mechanical damage (scratches), as well as from contamination. Laserdiscs store information that was recorded on them during the manufacturing process. Writing new information to them is not possible. Such discs are produced by stamping. There are CD-R and DVD-R discs that can only be written to once. On CD-RW and DVD-RW discs, information can be written/overwritten multiple times. Disks of different types can be distinguished not only by marking, but also by the color of the reflective surface.

Flash based devices.

Flash memory is a non-volatile type of memory that allows data to be written and stored on chips. Devices based on flash-memory have no moving parts, which ensures high data safety when used in mobile devices.

Flash memory is a microchip placed in a miniature package. To write or read information, the drives are connected to a computer via a USB port. The information capacity of memory cards reaches 1024 MB.

Information carriers - material that is intended for recording, storage and subsequent reproduction of information.

Information carrier - a strictly defined part of a particular information system, which serves for intermediate storage or transmission of information.

Information carrier is the physical environment in which it is fixed.

The media can be paper, film, brain cells, punched cards, punched tapes, magnetic tapes and disks or computer memory cells. Modern technology offers more and more new types of information carriers. To encode information, they use the electrical, magnetic and optical properties of materials. Carriers are being developed in which information is recorded even at the level of individual molecules.

In modern society, there are three main types of information carriers:

1) Perforated - have a paper basis, information is entered in the form of punches in the corresponding line and column. The amount of information is 800 bits or 100 KB;

2) Magnetic - as they are used floppy magnetic disks and cassette magnetic tapes;

3) optical.

Information carriers include:

Magnetic disks;

- magnetic drums- an early form of computer memory, widely used in the 1950s-1960s. Invented by Gustav Tauschek in 1932 in Austria. Subsequently, the magnetic drum was supplanted by memory on magnetic cores.

- floppy disks- a portable magnetic storage medium used for multiple recording and storage of data of relatively small volume. Recording and reading is carried out using a special device - a disk drive;

- magnetic tapes- a magnetic recording medium, which is a thin flexible tape, consisting of a base and a magnetic working layer;

- optical discs- an information carrier in the form of a disk with a hole in the center, information from which is read using a laser. The CD was originally created for digital audio storage, but is now widely used as a general purpose storage device;

- flash memory- a kind of solid-state semiconductor non-volatile rewritable memory. Flash memory can be read as many times as desired, but it can only be written to a limited number of times (usually about 10,000 times). Erasure occurs in sections, so you cannot change one bit or byte without rewriting the entire section.

All media can be divided into:

1. Human readable (documents).

2. Machine-readable (machine) - for intermediate storage of information (disks).

3. Human-machine-readable - combined media for highly specialized purposes (forms with magnetic stripes).

However, the rapid development of computer technology erased the line between the 1st and 3rd groups - a scanner appeared that allows you to enter information from documents into the computer's memory.

All currently available information carriers can be divided according to various criteria. First of all, one must distinguish volatile And non-volatile information accumulators.

Non-volatile drives used for archiving and storing data arrays are divided into:

1. by type of record:

– magnetic storage devices (hard disk, floppy disk, removable disk);

– magneto-optical systems, also called MO;

– optical, such as CD (Compact Disk, Read Only Memory) or DVD (Digital Versatile Disk);

2. by construction methods:

– a rotating platter or disk (like a hard disk, floppy disk, removable disk, CD, DVD, or MO);

– tape media of various formats;

- drives without moving parts (for example, Flash Card, RAM (Random Access Memory), which have a limited scope due to relatively small amounts of memory compared to the above).

If fast access to information is required, such as when outputting or transmitting data, then media with a rotating disk is used. For archiving performed periodically (Backup), on the contrary, tape media are more preferable. They have large amounts of memory combined with a low price, however, with relatively low performance.

According to the purpose, information carriers are divided into three groups:

1. Spread of information: media with pre-recorded information such as CD ROM or DVD-ROM;

2. archiving: media for one-time recording of information, such as CD-R or DVD-R (R (record able) - for recording);

3. backup (Backup) or data transfer: media with the ability to rewritable information, such as floppy disks, hard disk, MO, CD-RW (RW (rewritable) - rewritable and tapes.

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COURSE WORK

TYPES OF INFORMATION CARRIERS

Introduction

1. History

4.4 Removable magnetic disks

6. Solid State Drive

Conclusion

Bibliography

Introduction

An information carrier is a physical medium that directly stores information. The main carrier of information for a person is his own biological memory (human brain). A person's own memory can be called working memory. Here the word "operational" is synonymous with the word "fast". Learned knowledge is reproduced by a person instantly. We can also call our own memory internal memory, since its carrier - the brain - is inside us.

An information carrier is a strictly defined part of a specific information system that serves for intermediate storage or transmission of information.

The basis of modern information technology is the computer. When it comes to computers, we can talk about storage media as external storage devices (external memory). These data carriers can be classified according to various features, for example, according to the type of execution, the material from which the carrier is made, etc.

The main function of the computer's external memory is the ability to store a large amount of information (programs, documents, audio and video clips, etc.) for a long time. A device that provides recording - reading information is called a drive or disk drive, and information is stored on media (for example, floppy disks).

In the course of the abstract, we will consider the main types of information carriers.

1. History

The need to exchange information, preserve written evidence of one's life, etc. has always existed in man. Throughout the history of mankind, many information carriers have been tried. Since the carrier has a number of parameters, the evolution of the information carrier was determined by what requirements were imposed on it.

Ancient times. Ancient people depicted on the rocks the animals they hunted. However, charcoal, clay, chalk drawings were washed away by rain, and to increase the reliability of information storage, primitive artists began to carve animal silhouettes on the rocks with a sharp stone. Although the stone improved the safety of information, the speed of its recording and transmission left much to be desired. A person began to use clay for recording, which had the properties of a stone (preservation of information), and its plasticity, ease of recording made it possible to increase the efficiency of recording.

The ability to write effectively contributes to the emergence of writing. More than five thousand years ago (the achievement of the Sumerian civilization, the territory of modern Iraq) writing on clay appeared (no longer drawings, but icons and pictograms similar to letters). The Sumerians squeezed out signs on wet clay tablets with a reed stick pointed in a “wedge” (hence the name - cuneiform). The boxes (“folders”) contained large documents of dozens of clay “pages”. Clay was heavy for large texts, the need for which was growing. Therefore, another carrier had to come to replace it.

Egypt: papyrus. At the beginning of the third millennium BC. e. in Egypt, a new carrier appears, which has some improved parameters compared to clay tablets. They learned how to make almost real paper from papyrus (a tall herbaceous plant). The disadvantage of this carrier was that over time it darkened and broke. An additional disadvantage was that the Egyptians imposed a ban on the export of papyrus abroad.

Asia. The shortcomings of information carriers (clay, papyrus, wax) stimulated the search for new carriers. This time, the principle “everything new is well forgotten old” worked: in Persia, defter was used for writing since ancient times - dried animal skins (in Turkish and related languages, the word “defter” still means a notebook), which the Greeks remembered. The inhabitants of the Greek city of Pergamum (the first to adopt the ancient technology) improved the process of dressing skins and in the 2nd century BC. e. began the production of parchment. The advantages of the new medium are high reliability of information storage (strength, durability, did not darken, did not dry out, did not crack, did not break), reusability (for example, in a surviving prayer book of the 10th century, scientists found several layers of records made up and down, erased and cleaned, and with the help of x-rays, the oldest treatise of Archimedes was discovered there).

As in other countries, many different ways of recording and storing information have been tried in Southeast Asia:

Burning on narrow bamboo plates with fastening with cords into “bamboo books” (disadvantage - they take up a lot of space, low wear resistance of cords);

A letter on: silk (the disadvantage is the high cost of silk), palm leaves sewn into a “book”.

Due to the shortcomings of the previous carriers, the Chinese emperor Liu Zhao ordered that a worthy replacement be found for them, and one of the officials (Cai Lun) in 105 AD. e. developed a method for the production of paper (which has not changed much to this day) from wood fibers, straw, grass, moss, rags, tow, plant waste, etc.

Europe. On the territory of Europe, highly developed peoples (Greeks and Romans) groped for their own ways of recording. Many different media are replaced: lead sheets, bone plates, etc.

Starting from the 7th century BC e. the recording is made with a sharp stick - a stylus (as well as on clay) on wooden planks covered with a layer of pliable wax. The information was erased with the reverse blunt end of the stylus. These boards were fastened in four pieces. However, inscriptions on wax are short-lived, and the problem of preserving records was very urgent.

America. In the XI - XVI centuries. the indigenous peoples of South America came up with the knot letter "kipu" (translated from the language of the Quechua Indians - a knot). From the ropes (rows of laces were tied to them) “messages” were compiled. The type, number of knots, colors and number of threads, their location and weave was the "encoding" ("alphabet") of the kipu.

Native American tribes of North America encoded their messages with small shells strung on cords. This type of writing was called "wampum" - from the Indian word wampam - white beads. The interlacing of cords formed a strip, which was usually worn as a belt. A combination of colored shells and drawings on them could compose entire messages.

Ancient Russia. As a carrier in Russia, birch bark was used (the upper layer of birch bark). The letters on it were cut through with writing (a bone or metal stick). Knot writing was also used, the expression "tie a knot in memory" is still preserved.

By the end of the XVI century. paper appears.

Middle Ages. Both in the ancient world and in the Middle Ages, wax tablets were used as notebooks, for household notes and for teaching children to write.

New time. In the 20th century, thin iron wire (20s), magnetic tape (1928), magnetic (mid-1960s) and optical disks (early 1980s) began to be used to store information. In 1945, John von Neumann (1903-1957), an American scientist, put forward the idea of ​​using external storage devices to store programs and data. Neumann developed a structural schematic diagram of a computer. Neumann's scheme is consistent with all modern computers.

Modernity. In the 21st century, optical and magnetic media have been replaced by semiconductor memory chips. Hard drives are beginning to be replaced by similar semiconductor ones.

Historically, the first storage media were punched tape and punched card input-output devices. They were followed by external recording devices in the form of magnetic tapes, removable and permanent magnetic disks, and magnetic drums.

Magnetic tapes are stored and used wound on reels. Two types of coils were distinguished: supply and receive. Tapes are delivered to users on supply reels and do not require additional rewinding when installing them in drives. The tape is wound on the reel with a working layer inside. Magnetic tapes are non-direct access drives. This means that the search time for any record depends on its location on the media, since the physical record does not have its own address and in order to view it, you need to look at the previous ones. Direct access storage devices include magnetic disks and magnetic drums. Their main feature is that the search time for any record does not depend on its location on the media. Each physical record on the media has an address that provides direct access to it, bypassing the rest of the records. The next type of recording devices were removable magnetic disk packs, consisting of six aluminum disks. The capacity of the entire package was 7.25 MB.

2. Classification of information carriers

A variant of the classification of information carriers used in computer technology is shown in the figure:

According to the waveform used to record data, a distinction is made between analog and digital media. To rewrite information from analog to digital media or vice versa, a signal is needed.

Digital storage media - CDs, floppy disk, memory cards

Analog storage media - tape recorder and reel cassette

According to the purpose, carriers are distinguished:

For use on various devices;

Built into a specific device.

According to the stability of the recording and the possibility of rewriting:

Read Only Memory (ROM) whose content cannot be changed by the end user (eg CD-ROM, DVD-ROM). ROM in the operating mode allows only reading information;

Recordable devices into which the end user can write information only once (for example, CD-R, DVD-R, DVD + R, BD-R);

Rewritable devices (eg CD-RW, DVD-RW, DVD+RW, BD-RE, magnetic tape, etc.);

Operational devices provide a mode of recording, storing and reading information in the process of its processing. Fast but expensive RAM (SRAM, static RAM) are based on flip-flops, slow but cheap varieties (DRAM, dynamic RAM) are built on the basis of a capacitor. In both types of RAM, information disappears after being disconnected from the current source. Dynamic RAM requires periodic content refresh - regeneration.

According to the physical principle:

Perforated (with holes or cutouts) - punched card, punched tape;

Magnetic - magnetic tape, magnetic disks;

Optical - optical discs CD, DVD, Blu-ray Disc;

Magneto-optical - magneto-optical CD (CD-MO);

Electronic (use semiconductor effects) - memory cards, flash memory.

By design (geometric) features:

Disk (magnetic disks, optical disks, magneto-optical disks);

Tape (magnetic tapes, punched tapes);

Drum (magnetic drums);

Bartoque (bank cards, punched cards, flash cards, smart cards);

Sometimes information carriers are also called objects, reading information from which does not require special devices - for example, paper media.

The capacity of a digital medium means the amount of information that can be written to it, it is measured in special units - bytes, as well as in their derivatives - kilobytes, megabytes, etc., or in kibibytes, mebibytes like that. For example, the capacity of common CD - media is 650 or 700 MB, DVD-5 - 4.37 GB, dual-layer DVD 8.7 GB, modern hard drives - up to 10 TB (for 2009).

3. Tape media

Tape media is used for backup to ensure the safety of data. As such devices, a streamer is used, the information carrier in them is magnetic tapes in cassettes (up to 60 GB) and tape cartridges (up to 160 GB).

Magnetic tape - a magnetic recording medium, which is a thin flexible tape consisting of a base and a magnetic working layer. The working properties of a magnetic tape are characterized by its sensitivity during recording and signal distortion during recording and playback. The most widely used is a multilayer magnetic tape with a working layer of needle-like particles of magnetically hard powders of gamma-iron oxide, chromium dioxide and gamma-iron oxide modified with cobalt, usually oriented in the direction of magnetization during recording.

4. Disk media

Disk media are flexible and hard, removable and non-removable, magnetic, magneto-optical and optical disks and floppy disks.

Disk media refers to machine media with direct access. The concept of direct access means that the PC can "access" the track on which the section with the required information begins or where new information needs to be written.

There are other types of disk storage media, for example, magneto-optical disks, but due to their low prevalence, we will not consider them. carrier information flexible rigid

4.1 Floppy disk drives

This device uses floppy disks as a storage medium - floppy disks, which can be 5 or 3 inches. A floppy disk is a magnetic disk like a record placed in an "envelope". Depending on the size of the diskette, its capacity in bytes changes. If up to 720 KB of information fits on a standard 5"25" floppy disk, then 1.44 MB is already on a 3"5" floppy disk. Floppy disks are universal, suitable for any computer of the same class equipped with a disk drive, they can be used for storing, accumulating, distributing and processing information. The drive is a parallel access device, so all files are equally easily accessible. The disk is covered on top with a special magnetic layer that provides data storage. Information is recorded on both sides of the disc along tracks that are concentric circles. Each track is divided into sectors. The density of data recording depends on the density of tracks on the surface, i.e. the number of tracks on the disc surface, as well as the density of information recording along the track. The disadvantages include a small capacity, which makes long-term storage of large amounts of information almost impossible, and the not very high reliability of the floppy disks themselves. Currently, floppy disks are practically not used.

Some time ago, floppy disks were the most popular means of transferring information from computer to computer. the Internet was a rarity in those days, computer networks too, and devices for reading and writing compact discs were very expensive.

A floppy disk is a portable magnetic storage medium used for multiple recording and storage of relatively small data. This type of carrier was especially common in the 1970s and early 2000s.

Diskettes require careful handling. They may be damaged if the recording surface is touched; write on the floppy disk label with a pencil or ballpoint pen; bend a diskette; overheat the floppy disk (leave it in the sun or near the radiator); expose the disk to magnetic fields.

In order to preserve information, floppy magnetic disks should be protected from strong magnetic fields and heat, as this can lead to demagnetization of the media and loss of information.

4.2 Hard disk drives

If floppy disks are a means of transferring data between computers, then a hard disk is an information warehouse of a computer.

Hard magnetic disks are intended for permanent storage of information frequently used in work and represent a package of 4-16 disks rigidly fastened together, placed in a hermetic case. The first hard magnetic disks consisted of two disks with a diameter of 3.5 inches and got their name from the famous Winchester double-barreled shotgun. They had a volume of 5 - 10 MB. In the future, the number of disks and the capacity of "hard" drives increased, while the capacity of modern devices varies from 40 to 200 or more GB.

It is a logical continuation of the development of magnetic information storage technology. Main advantages:

Large capacity;

Ease and reliability of use;

Ability to access multiple files at the same time;

High speed data access.

Of the shortcomings, one can single out only the lack of removable storage media, although external hard drives and backup systems are currently used.

The computer provides the ability to conditionally split one disk into several using a special system program. Such disks that do not exist as a separate physical device, but represent only a part of one physical disk, are called logical disks. Names are assigned to logical disks, which are the letters of the Latin alphabet [C:], , [E:], etc.

4.3 Optical disc drives

Compact disc ("CD", "Shape CD", "CD-ROM", "CD ROM") is an optical storage medium in the form of a disk with a hole in the center, information from which is read using a laser. The CD was originally created for digital audio storage (Audio-CD), but is now widely used as a general purpose storage device (CD-ROM). Audio CDs are formatted differently from data CDs, and CD players can usually only play them (you can, of course, read both types of CDs on a computer). There are discs containing both audio information and data - you can listen to them on a CD player and read them on a computer.

Optical discs usually have a polycarbonate or glass heat-treated base. The working layer of optical discs is made in the form of the thinnest films of fusible metals (tellurium) or alloys (tellurium-selenium, tellurium-carbon, etc.), organic dyes. The information surface of optical discs is covered with a millimeter layer of durable transparent plastic (polycarbonate). In the process of recording and playback on optical discs, the role of the signal converter is performed by a laser beam focused on the working layer of the disc into a spot with a diameter of about 1 μm. As the disk rotates, the laser beam follows along the disk track, the width of which is also close to 1 µm. The ability to focus the beam into a small spot makes it possible to form marks on the disk with an area of ​​1 - 3 μm. Lasers (argon, helium-cadmium, etc.) are used as a light source. As a result, the recording density is several orders of magnitude higher than the limit provided by the magnetic recording method. The information capacity of an optical disk reaches 1 GB (with a disk diameter of 130 mm) and 2 - 4 GB (with a diameter of 300 mm).

Magneto-optical compact discs of the RW (Re Writeble) type have also been widely used as an information carrier. Information is recorded on them by a magnetic head with the simultaneous use of a laser beam. The laser beam heats up a point on the disk, and the electromagnet changes the magnetic orientation of that point. Reading is performed by a laser beam of lower power.

In the second half of the 1990s, new, very promising carriers of documented information appeared - digital universal video discs DVD (Digital Versatile Disk) of the DVD-ROM, DVD-RAM, DVD-R type with a large capacity (up to 17 GB).

According to the technology of application, optical, magneto-optical and digital CDs are divided into 3 main classes:

1. Disks with permanent (non-erasable) information (CD-ROM). These are plastic CDs with a diameter of 4.72 inches and a thickness of 0.05 inches. They are made using an original glass disc, on which a photo-recording layer is applied. In this layer, the laser recording system forms a system of pits (marks in the form of microscopic depressions), which is then transferred to replicated copy discs. Reading information is also carried out by a laser beam in the optical drive of a personal computer. CD-ROMs usually have a capacity of 650 MB and are used for recording digital audio programs, computer software, etc.;

2. Discs that allow one-time recording and multiple playback of signals without the possibility of erasing them (CD-R; CD-WORM - Write-Once, Read-Many - recorded once, counted many times). They are used in electronic archives and data banks, in external computer drives. They are a base made of a transparent material on which a working layer is applied;

3. Reversible optical discs that allow multiple recording, playback and erasing of signals (CD-RW; CD-E). These are the most versatile discs that can replace magnetic media in almost all areas of application. They are similar to write-once discs, but contain an operating layer in which the physical write processes are reversible. The manufacturing technology of such discs is more complicated, so they are more expensive than record-once discs.

Currently, optical (laser) discs are the most reliable material carriers of documented information recorded digitally. At the same time, work is underway to create even more compact information carriers using the so-called nanotechnologies that work with atoms and molecules. The packing density of elements assembled from atoms is thousands of times greater than in modern microelectronics. As a result, one CD made using nanotechnology can replace thousands of laser discs.

4.4 Removable magnetic disks

These are ZIP and JAZ floppy disks, with a diameter of 3.5”, with a capacity of 25-270 MB or more, incompatible with floppy disks. The rotation speed is 2941 rpm, the average search time is 29 ms. Designed for long-term storage of information and its transfer to other PCs. Many people use Zip devices - these are magnetic floppy disks that have a high capacity. It works like a simple floppy disk. Readability problems can be the same as with discs.

5. Electronic media

Generally speaking, all the carriers considered earlier are also indirectly related to electronics. However, there is a type of media where information is stored not on magnetic optical disks, but in memory chips. These microcircuits are made using FLASH technology, so such devices are sometimes called FLASH disks (popularly just a "flash drive"). The microcircuit, as you might guess, is not a disk. However, operating systems define storage media with FLASH memory as a disk (for user convenience), so the name "disk" has the right to exist.

Flash memory (eng. Flash-Memory) - a kind of solid-state semiconductor non-volatile rewritable memory. Flash memory can be read as many times as desired, but it can only be written to a limited number of times (usually about 10,000 times). Despite the fact that there is such a limit, 10 thousand rewrite cycles is much more than a floppy disk or CD-RW can withstand. Erasure occurs in sections, so you cannot change one bit or byte without rewriting the entire section (this limitation applies to the most popular type of flash memory today - NAND). The advantage of flash memory over conventional memory is its energy independence - when the power is turned off, the contents of the memory are preserved. The advantage of flash memory over hard drives, CD-ROMs, DVDs is that there are no moving parts. Therefore, flash memory is more compact, cheaper (including the cost of read-write devices), and provides faster access. Unlike magnetic, optical and magneto-optical media, it does not require the use of disk drives using complex precision mechanics. They are also distinguished by silent operation.

The most popular and cheapest medium is a memory chip with a control controller and a USB connector. They vary widely in capacity (from 1 to 256 GB), but often users forget about one more main parameter of a flash drive - its speed. As a rule, the write speed of such drives is 5 - 7 Mb / s, and the read speed is 15 - 20 Mb / s. When choosing, you should pay attention to labels such as "ultra fast" and "high-speed". These devices are fast. This type of media stops working mainly due to the blocking of the control controller - they last for about 5 years, while it is not recommended to use them as archiving devices. A flash drive, like its "relative" - ​​a memory card, always "dies" entirely.

6. Solid State Drive

A solid-state drive (SSD) is a computer non-mechanical storage device based on memory chips. In addition to them, the SSD contains a control controller. The most common type of solid state drives uses NAND flash memory to store information, however, there are options in which the drive is created on the basis of DRAM memory equipped with an additional power source - a battery.

Currently, solid-state drives are used not only in compact devices - laptops, netbooks, communicators and smartphones, tablets, but can also be used in desktop computers to increase productivity.

Compared to traditional hard disk drives (HDDs), solid state drives are smaller and lighter, but several times (6 - 7) times more expensive per gigabyte and significantly less durable (recording resource).

Small solid-state drives can be built into the same chassis with magnetic hard drives, forming hybrid hard drives (SSHD, Solid-state hybrid drive). Flash memory in them can be used either as a small buffer (cache) (4 - 8 GB), or, less often, be available as a separate drive (Dual-drive hybrid systems). This combination allows you to take advantage of some of the benefits of flash memory (fast random access) while keeping the cost of storing large amounts of data low.

Currently, the most notable companies that are intensively developing the SSD-drive business in their activities are Intel, Kingston, Samsung Electronics, Toshiba, SanDisk, Corsair, Renice, OCZ Technology, Crucial and ADATA.

In the early 2010s, SSDs with volumes of 64, 80, 120, 256, 512 gigabytes were introduced to the market, some models have a capacity of 0.7, 0.8, 1, 1.6 terabytes or more. In 2012, SSD shipments amounted to about 34 million devices, the main markets are: consumer, server, industrial applications. Prices for 128 GB SSD in 2013 were in the range of 70 - 85 US dollars.

Advantages.

1. No moving parts, hence:

Complete absence of noise (0 dB);

High mechanical resistance (short-term withstand about 1500 g);

2. Stability of file reading time regardless of their location or fragmentation.

3. The read/write speed is faster than common hard drives.

4. The number of random input / output operations per second (IOPS) for SSDs is several orders of magnitude higher than for hard drives.

5. Low power consumption.

6. Wide operating temperature range.

7. Much less sensitive to external electromagnetic fields.

8. Small dimensions and weight.

Disadvantages.

1. The price of a gigabyte of SSD drives is several times (6 -7 for the cheapest flash memory) higher than the price of a gigabyte of HDD (as of October 2014 - 35 cents per gigabyte). In addition, the cost of SSDs is directly proportional to their capacity, while the cost of traditional hard drives depends not only on the number of platters and grows more slowly with increasing storage capacity.

2. The use of the TRIM command in SSD drives can greatly complicate or make it impossible to recover deleted information using recovery utilities.

3. The inability to recover information in case of electrical damage. Since the controller and storage media in the SSD are on the same board, if the voltage is exceeded or significant, the entire SSD drive most often burns out with irretrievable loss of information. On the contrary, in hard drives, only the controller board burns out more often, which makes it possible to restore information with acceptable labor intensity.

Conclusion

Having considered this topic, we can say that with the development of science and technology, new information carriers will appear, more advanced, which will replace the outdated information carriers that we use now.

The wide distribution of optical discs is associated with a number of their advantages compared to magnetic media, namely: high storage reliability, large amount of stored information, recording sound, graphic and alphanumeric on one disc, search speed, economical means of storing and providing information. , they have a good quality-price ratio.

As for hard disks, no computer has yet managed without them. In the development of hard disks, the main trend is clearly visible - a gradual increase in recording density, accompanied by an increase in the speed of rotation of the spindle head and a decrease in information access time, and ultimately - an increase in performance. The creation of new technologies is constantly improving this media, it changes its capacity to 80 - 175 GB. In a more distant future, a carrier is expected to appear, in which the role of magnetic particles will be played by individual atoms.

As a result, its capacity will be billions of times higher than current standards.

There is also one advantage: lost information can be recovered using certain programs.

Improving flash memory technology is in the direction of increasing the capacity, reliability, compactness, versatility of media, as well as reducing their cost.

At the development stage are holographic digital media with a capacity of up to 200 GB. They have the shape of a disk, consisting of three layers. A 0.2 mm thick recording (working) layer and a half-millimeter transparent protective layer with a reflective coating are applied to a 0.5 mm thick glass substrate.

Bibliography

1. Ross G.V. "Fundamentals of Informatics and Programming" / G.V. Ross, V.N. Dulkin, L.A. Sysoeva - M.: PRIO, 1999

2. Informatics: Textbook. - 3rd revised ed. / ed. N.V. Makarova - M.: Finance and Statistics, 2002

3. Levin V.I. "Information carriers in the digital age" / V.I. Levin - M.: ComputerPress, 2000. - 256 p.

4.https://en.wikipedia.org

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May 2009

The more firmly digital technology enters the life of offices, the more actively they begin to use a wide variety of information media. Floppy disks were the first to appear on the office goods market, then they were addedCD andDVDs are now confidently coming into use as flash drives. Undoubtedly, in some cases, certain information storage devices turn out to be much more effective, and in some cases even an indispensable tool for working with various materials, which leads to an increase in demand for this type of product in the office segment and, accordingly, the introduction into the range and gradual expansion line of information carriers by operators of the market of goods for the office. Read about the situation in this segment of computer accessories, features of the offer, demand trends and development prospects in the current product review.

General situation

"Information carriers" are one of the most dynamically developing product groups: the first floppy disks did not have time to appear, as manufacturers brought out the following type of product - CDs and DVDs, and then USB drives and memory cards, external hard drives. What used to be often perceived as “luxury” in work is now becoming the norm of life and its invariable attribute, natural, like a pen or paper. That is why stationery companies have recently begun to introduce and develop the “Information Carriers” product line into their assortment, although in fairness it should be noted that far from all players of the stationery and office market can “boast” of a good selection of this type of product in the assortment.

Nevertheless, there is a growing interest in this group of goods among operators of the stationery market, as evidenced by experts from companies specializing in the distribution of computer equipment and accessories and supplying storage media, including to “clerical workers”.

“At the moment, the share of stationery companies offering storage media is small,” notes product manager for flash products at AKCent" Sergey Roshchin. “Although in the near future it can be significantly expanded due to the fact that flash drives are beginning to move from the category of computer accessories to the category of consumables that are vital for the modern office.”

“There are many stationery companies among our clients, and they occupy a significant share in the Information Carriers group,” says Merlion Business Development Department Manager Olga Shipulina. - In the near future, their share is likely to only grow, as storage media are increasingly moving into the stationery segment from the segment of technically complex goods, - she continues. - First of all, this applies to flash memory, as well as high-capacity USB hard drives - from 160 GB to 2 TB. This is the fastest growing segment, which has shown significant growth over the past six months or a year.”

The rapid development of the "Flash drives" group as one of the segments of the "Information carriers" and the tendency for them to crowd out other storage media is also noted. Sergey Roshchin (AK Cent), stating that they are increasingly competing with CDs and DVDs, especially in the low price segment.

Since information carriers are relatively new products for operators of the stationery market, it is impossible to talk about its saturation with this type of product. “The saturation of the market is low and many companies represent this segment rather narrowly,” states Alexei Tokarev, Head of Office Equipment Department, SAMSON Group of Companies. - Although the assortment of our company contains almost the entire range of storage media - floppy disks, CD-R / RW-, DVD-R / RW-disks, memory cards, and USB drives, and in the near future it is planned to introduce portable hard drives. “When it comes to flash drives, the market is also far from saturated,” adds Sergey Roshchin (AK Cent).

Perhaps that is why storage media is the most profitable group in the "Computer Accessories" segment, as also evidenced by experts. “In the Computer Accessories segment, the Information Carriers group is one of the most profitable,” notes Alexey Tokarev ("SAMSON"). "Flash cards, USB sticks and external HDDs and SSDs make up over half of our portfolio and are clearly the top performers in terms of profits," states Sergey Roshchin (AKCent"). “Profitability in this segment is traditionally good, and this is also why the product group is developing dynamically,” confirms Olga Shipulina (Merlion).

Players & Demand Features

Diagram 1. Shares of different consumer groups in the total flow of demand for information carriers (according to the data of the company "AK Cent")

The composition and shares of players in different subgroups of information carriers vary. If we talk about the subgroup "Diskettes", then, according to Alexey Tokarev ("SAMSON"), the most popular brands are Verbatim, Imation, Emtec/BASF, TDK, SONY. “Verbatim is leading the way with about 25% of all sales,” he adds.

“The market for recordable optical media (CD/DVDs) is divided into two segments: no name discs and products from well-known companies such as TDK or Verbatim. In the first segment, only the price matters, while in the second segment, the emphasis is on the brand image,” he continues.

If we talk about the group "Flash drives", then here, according to Sergey Roshchin (AK Cent), leading brands are Transcend and Kingston, which occupy approximately 30% of the flash memory market each. “Followed by such brands as Sony - 10%, Apacer - 7%, A-Data - 5%, as well as a number of others, the share of which is in the range up to 5%: OCZ, SanDisk, PQI, etc.", he adds.

Sergey Roshchin: Remember when was the last time you bought pens or post-it blocks for your home? What for? After all, they are issued with the company logo at work. The same will soon happen with USB drives. They just don't have the manufacturer's logo on them.

According to Olga Shipulina (Merlion), the picture with the distribution of shares between the players today is not so clear. “In the current volatile environment, it's impossible to say anything with certainty about market shares or established demand and market segments, and the Media Group is no exception,” she notes. “Now the products of cheap brands are becoming more and more in demand, because in addition to the low price, they also began to offer good design today and “pulled themselves up” in product quality.”

In addition to foreign players, domestic manufacturers also present their products on the Russian market. However, as rightly noted Sergey Roshchin (AK Cent), there is no need to talk about their significant share. “In most cases, these are Private Labels of domestic distributors and retailers,” he adds.

The competition between the players is quite tough. “In the flash memory market, this is due to a fairly large number of distributors and the predominance of price competition in the market,” analyzes Sergey Roshchin (AK Cent). - In the low price segment of capacities up to 2 GB, competition is so intense that many distributors work exclusively with the most popular positions in the middle and upper price ranges, - he continues. - As for our company, we try to maintain the maximum range of products for each vendor, which, coupled with an attractive price, allows us to maintain a leading position in the market for many years. Regarding no name products, we can say that its main consumers are advertising agencies and the corporate sector, which is engaged in applying their own logos to these flash drives. Now flash drives with the company logo are becoming a fairly common element of corporate style, along with pens and diaries.

Scheme 1. Classification of information carriers

Quite a strong competition exists in the segment of CD- and DVD-discs, and the main struggle also takes place between branded and no name products. In this regard, the situation in the segment of floppy disks, which, due to their low cost and limited demand, is probably of no particular interest to manufacturers of non-branded products, remains the calmest.

Analyzing the distribution of demand for flash drives, Sergey Roshchin (AK Cent) notes that, according to a rough estimate, up to 60-70% of demand falls on Moscow and the region, the rest is other regions. “However, smaller distribution companies purchasing goods in Moscow are engaged in further distribution of goods, including in the regions,” he notes. - The same can be said about federal retail and cellular networks. Therefore, it is approximately possible to estimate the shares of consumption of "flash" in Moscow, the Moscow region and in other regions of Russia as equal.

The growth in demand for information carriers in the regions is also evidenced by Olga Shipulina (Merlion). “There was a pent-up demand in the regions when the consumer began to buy high-tech goods and, accordingly, the demand for information carriers increased,” she states.

Speaking about the peculiarities of the demand for information carriers, Sergey Roshchin (AK Cent) draws attention to the fact that the demand for flash memory has a pronounced seasonality. “In the spring-summer period, sales of flash cards predominate, and in the autumn-winter period, USB drives dominate,” he explains. “This is partly due to the specifics of using these devices: in the summer, during the holidays, cards for cameras and phones are needed, and in the fall, schoolchildren and students buy USB drives for data exchange.”

At the same time, it is in the segment of flash drives, as the most dynamically developing and the most expensive one, that today we can talk about the highest level of requirements for product quality. Although, according to Sergei Roshchina (AK Cent), and it is not the main one. “Most flash drives become obsolete morally much faster than they physically fail, and the warranty period for some of them extends to the entire period of operation,” he explains. - In general, for flash cards, the quality indicator is the data transfer speed, for USB drives - the design and quality of its execution: material, assembly, sometimes even packaging.

floppy disks

“At the end of the last decade, computer market experts unanimously assured: the time for 3.5-inch floppy disks or, in other words, floppy disks is running out - another year or two, and they will be completely ousted from the market,” says Alexey Tokarev ("SAMSON"). "The floppy disk market is indeed shrinking, but much slower than predicted."

Today, according to Alexey Tokarev ("SAMSON"), the volume of the Russian floppy disk market ranges from 2 to 3 million media per month. "Experts cite several reasons for the relentless popularity of floppy disks," he continues. - Firstly, it is quite low cost compared to alternative devices such as flash memory and magneto-optical disks. Secondly, floppy disks are often used to store information that can be used to restore a computer to working capacity after a failure. But the most important reason for the “survivability” of floppy disks is, perhaps, the cheapness of disk drives that sell for no more than $10,” he concludes.

One way or another, but floppy disks today have retained several niches that allow them to occupy a relatively stable market share for the time being. The demand for them is maintained thanks to:

Government agencies in which the computer park is very budgetary, and therefore 3.5" floppy disks are used for file exchange;

Individual universities, especially peripheral ones, in which students resort to the use of diskettes as a practically uncontested means for transferring term papers or other work;

Some areas (for example, banking), where software is still used that requires a key floppy disk to access the program or any data;

Computer "enthusiasts" who sometimes keep a disk drive in their computer, since all operating systems up to Windows XP only accept drivers (at the installation stage) from a floppy disk, and it is easier to create a bootable flash drive for Windows XP by first making a boot floppy disk.

Diagram 2. The share of different types of drives in the assortment of companies

Thanks to the above groups, floppy disks and floppy disk drives remain quite in demand today.

In the assortment of companies you can find black or assorted floppy disks (green, red, yellow, blue, orange, etc.) in a package. They can be sold both in cardboard packaging and in plastic boxes. However, all these "frills" today do not have a significant impact on demand. The classic black floppy disks packed in a more economical cardboard box remain the most popular.

Disks

Demand for CDs and DVDs is significantly higher than for floppy disks, although it can be noted that with the proliferation of higher-capacity DVDs, demand for CDs has stagnated. “The share of CDs has been declining in recent years, and no wonder. These media are no longer enough for large amounts of information, for example, for video, and the price of "blanks" is almost equal to the prices for more capacious media, states Alexey Tokarev ("SAMSON"). - Yes, and drives that do not support the work of DVDs are slowly becoming the property of history, - he continues. - However, in absolute terms, the supply of such media is still very high. This is largely due to the fact that a large number of household equipment purchased earlier does not understand other formats. In other words, if we need compatibility with an old household player or radio, then we need to buy a CD. And in general, in terms of ensuring maximum compatibility, this format remains the most optimal so far: any optical drive will read a CD. Plus, laptops with a combo drive are still being sold, so their owners, if they want to write something to the “optics”, have no choice,” he concludes.

Both those and other optical storage media have their advantages, and each gradually occupies its own niche in the market. CDs have more storage capacity than floppies and are not as expensive as DVDs. Therefore, they are the best option for recording and mass distribution of presentations, training programs, catalogs, promotional materials, applications for printed publications, as well as for creating archives, etc. -disks - DVDs” (see Diagram 4). DVD discs are used in areas where you have to work with large documents (for example, in design, engineering departments).

Blu-ray disc (BD disc)
Blu-ray technology uses a 405nm blue-violet laser to read and write. Conventional DVDs and CDs use red and infrared lasers at 650nm and 780nm respectively. Reducing the wavelength in the Blu-Ray technology made it possible to narrow the recording track by half compared to a conventional DVD disc and increase the data recording density. In other words, the shorter wavelength of the blue-violet laser allows more information to be stored on a 12cm Blu-Ray disc than on a CD/DVD of the same size.

If we analyze the range of CDs and DVDs offered on the office goods market today, we can note that the products are presented quite widely. These are, as a rule, several trademarks and no name products, covering all price segments and, accordingly, a different type of packaging with a different number of discs in the package itself.

The range of disposable CDs and DVDs is the most widely represented (when compared with the line of reusable discs): both in terms of the number of pieces in a package and the type of packaging, in terms of color, and the possibility of printing on the surface of the disk.

In the range of CD-R and DVD-R discs (disposable) in terms of the number of items in a package, the largest number of positions falls most often on packages of 10 discs. Products in packs of 25, 50 and 100 discs are also widely represented. At the same time, the cakebox is increasingly becoming the most popular type of packaging as it is cheaper, and with large “lots” of 50 and 100 discs, it is practically the only possible one. However, storing archival materials in "cakeboxes" in offices is quite inconvenient, as it makes it difficult to find and extract the desired disk from the total mass of "blanks" strung one on top of the other, like in a children's pyramid.

Some companies offer discs in shrink packaging, in which the discs are packaged by quantity and wrapped in a conventional shrink film - this is perhaps the most economical type of packaging, but it is quite rare in the supplier's product line. Such "blanks" will definitely require additional expenses for storage accessories - either plastic cases, or pockets for discs, or cases and special boxes.

Discs in jewel ("thick") and slim ("thin") plastic cases are usually offered in cardboard packages with a capacity of up to 10 pieces. According to Alexey Tokarev ("SAMSON"), slim cases are more compact and cheaper, so they are in great demand. In general, the advantage of discs in cases is that they can be sold without problems both in packages and individually - the case will protect the "blank" from mechanical damage during transportation and save the client from having to solve the problem of "what to wrap and put in" .

Of particular interest among disposable discs are media with the ability to print on the surface. As noted Alexey Tokarev ("SAMSON"), this type of optical media is in demand in the corporate segment.

CD-RW and DVD-RW- (reusable) discs are usually offered in much smaller quantities in a package and more often - by the piece and in jewel cases, since this type of box protects optical media from damage to the maximum.

It was the “reusability” of disks that determined the noticeably lower demand for them. Firstly, they can be used several times, and, accordingly, the need to buy more of them arises much less frequently, and secondly, they are, of course, more expensive than disposable discs, so they are bought precisely when there is a purposeful need to write several once. And if we take into account that more “advanced” storage media are presented on the market quite widely and at affordable prices, colloquially referred to as “flash drives”, which allow you to record much larger amounts of information, a much larger number of times, while the devices themselves are undoubtedly more compact. disks, and the information on them is more protected from mechanical influences. All this, ultimately, leads to the fact that the consumer is increasingly opting for "flash drives".

For the same reason, double-sided discs are not widely used. “Demand for these is quite limited due to the fact that they are expensive and there are currently other media that can provide more information storage,” notes Alexey Tokarev ("SAMSON").

Another existing type of disc is Blu-Ray or BD (from the English blue ray - "blue ray") - an optical media format used to record and store digital data, including high-definition video with increased density. This type of storage media is also present in the range of some companies, but has not yet received wide distribution for a number of reasons. "It's hard to say about the future of BD discs," comments Olga Shipulina (Merlion)- I think they are in demand and will remain in demand only in the segment of licensed films, games and other content sold only on discs.

According to the same Alexey Tokarev ("SAMSON"), drives for BD-discs are becoming more massive, the discs themselves are getting cheaper, so in the next couple of years "the format will continue to advance."

Flash drives, memory cards, portable hard drives

This segment of storage media, according to Sergey Roshchin (AK Cent), is distinguished by a constant downward price trend and a constant increase in the amount of memory of the digital media themselves. “Six months ago, the main sales accounted for 1 GB and 2 GB media, now the most popular volume is already 2 GB and 4 GB, and 1 GB has practically disappeared from the assortment,” he comments. “It is likely that by the end of the year it will be difficult to find a USB flash drive with a capacity of 2 GB, and 4 GB and 8 GB will be the best sellers.”

Alexey Tokarev ("SAMSON"), characterizing the specifics of the segment, adds that, unlike "optics", where there is a simple redistribution of market shares, the segment of flash drives is growing on its own. "The proliferation of digital cameras, flash card camcorders and other digital devices predicts significant growth in flash card sales," he adds.

According to Olga Shipulina (Merlion), the main advantage of flash memory over hard drives and CD-ROM media is that it consumes significantly (about 10-20 or more times) less energy during operation. “In addition, flash memory is smaller than most other mechanical media, more reliable and more durable,” she notes. “The information recorded on it can be stored from 20 to 100 years and is able to withstand significant mechanical loads, 5-10 times higher than the long-term allowable for conventional hard drives.”

Types of flash drives

	USB Flash Drive or USB flash drive (flash drive, USB drive, or "flash drive")- a storage medium that uses flash memory to store data and is connected to a computer or other reading device via a standard USB connector. It is the latter that distinguishes this type of storage media from memory cards.
	Multimedia Card (MMC)- portable memory card used in digital cameras, mobile phones, etc. Size 24x32x1.5 mm. Developed jointly by SanDisk and Siemens. The MMC contains a memory controller and is highly compatible with various types of devices. Generally, MMC cards are supported by devices with an SD slot. Three additional modifications of MMC cards: RS-MMC, MMCmobile and MMCmicro, which require an adapter to ensure compatibility with the standard MMC slot. RS-MMC(Reduced Size MultiMedia Card): half the length of a standard MMC card (reduced size = "reduced size"): 18x24x1.4 mm. All other characteristics do not differ from the characteristics of a "regular" MMC card. DV-RS-MMC(Dual Voltage Reduced Size MultiMedia Card): Dual voltage DV-RS-MMC memory cards (dual voltage = "double voltage": 1.8 and 3.3 V) have reduced power consumption and allow the device to work a little longer. The dimensions are the same as those of the RS-MMC. MMCmicro: a miniature memory card for mobile devices with even smaller dimensions than RS-MMC: 12x14x1.1 mm.
	SD card(Secure Digital Card) - Supported by SanDisk, Panasonic and Toshiba. It is a further development of the MMC standard. In terms of size and characteristics, they are very similar to MMC, only a little thicker (24x32x2.1 mm). The main difference is copyright protection technology (secure digital = "secure digital"), which allows you to protect access to the card with a password. Unlike MMC cards, SD cards are also equipped with a mechanical switch for write protection, file deletion, and card formatting. This type of protection is assigned to the device that works with the card, so it may not be implemented. In most cases, the SD can be replaced with an MMC card. Reverse replacement is usually not possible due to the thicker thickness of SD cards. There are 2 modifications of SD cards: SDTF(Trans-Flash) and SDHC(High Capacity = "high capacity") - SDTF and SDHC cards and their readers differ in the limitation on the maximum storage capacity - up to 2 GB for TF and up to 32 GB for HC. SDHC readers are backwards compatible with SDTF and will easily read an SDTF card, but an SDTF device will only see 2 GB of the SDHC capacity if it has a larger capacity, or will not be read at all. Both subformats can be of three sizes: standard SD (24x32x2.1 mm), miniSD (20x21.5x1.4 mm) and microSD (11x15x1 mm). An adapter is required for compatibility with the standard SDmini and micro slot.
	Memory Stick (MS)- a storage medium based on flash memory technology from Sony Corporation. Memory Stick media is used in camcorders, digital cameras, personal computers, printers, PSP game consoles, cell phones and other electronic devices primarily from Sony itself. Standard dimensions: 21.5x50x2.8 mm. MS Duo/MS Pro Duo- have smaller dimensions (20x31x1.6 mm) and high data transfer rate (up to 20 Mb/s). MSmicro- has even smaller dimensions (12.5x15x1.2 mm).
	Compact Flash (CF)- flash memory format, which appeared one of the first. Developed by SanDisk. Used in PDAs, digital video and photo cameras, printers, etc. Dimensions: 43x36x3.3 mm. One of the most important advantages of CF is compatibility with the PCMCIA-ATA standard, the most common for small devices.
	Smart Media (SM)- format developed by Toshiba. Unlike CF cards, SM cards do not have a built-in controller, which slightly worsens compatibility - older devices do not always understand high-capacity cards. Dimensions: 37x45x0.76 mm. Memory cards of this format are currently out of production.
	eXtreme Digital (хD), a new name - xD-Picture Card - the format is designed for use in Olympus and Fuji digital cameras. Other brands that make xD cards include Kodak, SanDisk, and Lexar. Developed as a replacement for the Smart Media format. Compared to SM, the xD format is more versatile, compact (size 20x25x1.7 mm), has a higher data transfer rate, reduced power consumption and a larger capacity. Unlike SD/MMC cards, xD cards are not equipped with a controller chip, and therefore they have a relatively small size and low speed performance compared to SD/MMC cards. The cost of xD cards is on average twice the cost of SD cards of the same size, despite the fact that XD cards do not have any special advantages over SD cards.

There are several types of flash drives. All of them can be conditionally divided into 3 groups: flash drives (or simply “flash drives”), memory cards and SSDs, which are often considered together with magnetic external HDD drives.

As noted Olga Shipulina (Merlion), for the office, the most popular are flash drives and external HDD and SSD drives. “Cards are less popular, as they are used more actively in multimedia devices: phones, smartphones, PDAs, photo and video equipment,” she adds.

SSD drive
(from English SSD, Solid State Drive, Solid State Disk) - a solid-state drive, a rewritable computer storage device without moving mechanical parts (unlike HDD). There are solid-state drives based on the use of volatile (RAM SSD) and non-volatile (NAND or Flash SSD) memory. "Stuffing" SSD physically has nothing to do with traditional hard drives (HDD) and is a flash memory array with a hard drive interface and access to a PC (via traditional SATA or PATA interfaces). Outwardly, it differs from HDD only in more compact dimensions. SSD has all the advantages and disadvantages of flash memory.

“Among USB drives, flash drives are in the lead - 80%,” states Sergey Roshchin (AK Cent). - Portable external hard drives (HDD) also find their buyers, which offer larger capacities (up to 1000 GB) with the convenience of conventional USB drives - 15%. The mass distribution of the latest SSD solid-state drives is still limited by a relatively high price compared to HDD, their share in the USB-drive market is still only 5%, but this type of media has a very great potential for development, since they have a USB interface, HDD volume -disk and flash memory, unlike HDDs that have mechanical elements.

Diagram 3. The ratio of USB-drives and memory cards in the range of companies

“Among flash cards, the undisputed leader is micro CD - about 50% of all card sales, - since they are used in almost every “mobile phone,” continues Sergey Roshchin (AK Cent). - Further, the most significant are Secure Digital memory cards used in professional photo equipment and communicators - 30%, MemoryStick (MS Pro Duo and MS Micro M2) due to their lobbying by SONY - 10%, and Compact Flash - 7%. The rest of the standards are now practically "extinct", - he states. “Nevertheless, MS Pro Duo and SD cards will be more interesting as an office option, which can be used to expand the memory of laptops and netbooks and, accordingly, their capabilities, since the capacity of flash media is sometimes comparable to the capacity of the built-in disk.”

In assessing the parameters that affect the choice of certain devices by customers, experts disagreed ( see table 1). Moreover, the evaluation of the parameters itself also caused difficulties, since in different situations, in relation to different types of flash drives and in different market segments, their significance varies. So, according to Sergey Roshchin (AK Cent), such a parameter as a brand turns out to be important mainly for corporate customers who have high requirements for reliability, for example, for banks or for tender deliveries, where a particular brand is clearly indicated. “Retail usually sells the brand that is on the counter and advertised by a skilled consultant,” he adds.

Moreover, according to Sergey Roshchin (AK Cent), it is difficult to determine the significance of such a parameter as the "capacity" of the drive. “Typically, the end user buys the highest capacity flash drive that they can afford to spend on it, whether that capacity is current or not,” he explains.

It is interesting to note that, unlike the demand for many other office products, the demand for storage media such as flash drives is often driven by packaging. “Packaging / blister - bright, stylized - is sometimes much more important than the brand and is on a par with the design of the flash drive itself,” emphasizes Sergey Roshchin (AK Cent). - Concerning product design, we can say that in the office segment drives in strict design and in classic colors and materials are more in demand - a simple plastic rectangle in black or corporate color. However, “flash drives” of an original design are often used as representative functions, for example, drives stylized as the company’s products, or “flash drives” with an expensive, exclusive case finish - for example, made of genuine leather or with Swarovski crystals. The importance of the materials from which the body of the product is made is evidenced by Olga Shipulina, arguing that they influence the choice of a particular drive in the same way as the brand and country of origin.

Diagram 4. The ratio of sales volumes of CD-/DVD-disks, floppy disks in 2008 in the assortment of SAMSON Group

Experts also draw attention to the fact that small flash drives are not so easy to use, and although they are present in the assortment of companies, they are in limited demand. “The very small size of a flash drive is more of a publicity stunt than a demanded necessity, and has a number of disadvantages: lower body strength, insecure USB connector, and, corny, such a flash drive is much easier to lose and harder to find in a pocket or bag,” - explains Sergey Roshchin (AK Cent).

Such a parameter as the speed of information exchange (read / write), according to Sergey Roshchin (AK Cent), does not significantly affect the choice of a USB drive and is of the greatest importance mainly when buying Compact Flash cards used in professional photographic equipment. “Otherwise, price is more important,” he adds. - At the same time, an increase in prices for the same type of product usually leads to a shift in demand for cheaper analogues, if these are mutually competing brands, such as Transcend and Kingston. Design and brand image play a less significant role here.”

When working with memory cards, you should remember a few basic rules:

• electrostatic discharge can damage electronic components, so before touching a memory card, you need to make sure that you are not static electricity by touching a grounded metal object;
• avoid touching the gold-plated contacts of the memory card;
• it is necessary to protect the memory card from sources of heat, direct sunlight, and humidity;
• do not bend and throw a memory card;
• you should never turn off the memory card during the transfer of information in order to avoid data loss or damage to the card itself;
• Before use, it is better to make sure that the card and the device are compatible.

Regarding the capacity of "flash drives", as noted earlier, the most popular at the moment are drives with a capacity of 2 GB and 4 GB, and models with a capacity of 8 GB are currently considered the most promising. Although, according to Sergey Roshchin (AK Cent), the presence of larger-capacity flash drives in the assortment is also necessary for the full assortment and the gradual “getting used” to them by the user.

Diagram 5. The share of USB-drives of different capacities in the range of companies

Conclusion

All experts admit that disks, just like floppy disks, will soon, if not become a thing of the past, be significantly replaced by flash drives. “Dynamics of demand will shift towards USB-flash and low-cost large-capacity memory cards, as well as low-cost portable USB HDDs up to 500 GB,” predicts Olga Shipulina (Merlion). And many factors, in her opinion, will contribute to this process: the market being filled with all kinds of devices that allow the use of memory cards, and the displacement of disks by “flash drives” and small SSD / HDD, and greater versatility and ease of use of these devices for all categories of consumers , and greater protection of the recorded information from mechanical influences.

The same opinion is shared by Sergey Roshchin (AK Cent), noting that the segment of flash media is just beginning to take shape. “As storage capacity grows and costs decrease, USB flash drives can significantly replace CDs as a tool for storing and transferring information outside the company (presentations, advertising, etc.),” he comments. - Without a doubt, this "souvenir" will be used repeatedly, unlike the disk, and this is a serious argument in favor of flash drives. Moreover, many modern laptops are starting to get rid of built-in DVD drives. And even “office blondes” understand the process of writing to a USB flash drive, which cannot be said about burning a CD or DVD.

Such a group of drives as flash drives for applying information to the case has special prospects. “Pretty soon, in most companies, flash drives with a company logo and a small presentation will be available to every employee, just like a pen and business cards,” predicts Sergey Roshchin (AKCent"). “And their sales to the corporate sector may be comparable to retail sales.”

We thank the companies "AK Cent", "Merlion", "SAMSON" for their help in preparing the product review.