Types of hard drives for a computer. What are the types of hard drives

Today we will learn what is called a computer hard drive or hard drive, what types of devices exist, what is the principle of operation, and also how to choose the right drive, based on technical characteristics and performance

WHAT IS A HARD DISK? FEATURES, TYPES, CHARACTERISTICS AND HOW TO CHOOSE?

Good afternoon, today we will find out what is called computer hard drive, hard drive or storage device, what kind varieties devices exist, what principle of operation and also how to select drive, based specifications and performance. In addition, let's talk about what different built-in hard drives from external hard drives what you need to pay attention to first of all before buying a device, as well as what benefits and shortcomings possess electronic storage. In conclusion, we will talk about which components consist of memory devices, as well as design features and parameters devices have.

Quite often, each of us is faced with such a life situation when the internal memory of a laptop or personal computer is almost 100 percent full, and we are not eager to format or delete the information we have. In this case, we have only one competent option left - this is the purchase of a new, more capacious computer drive. However, this task must be carried out in such a way that the problem of insufficient free space does not remind of itself for at least the next 5-6 years.

WHAT IS AN EXTERNAL BATTERY/POWERBANK

What is a computer hard drive, hard drive or drive? A hard disk drive, also known as a hard drive, is a special storage device for storing random access information, which is based on the principle of magnetic recording. The hard drive is by far the main storage device on most personal computers and laptops. The hard drive is an extension of floppy disk or floppy disk technology. The operation of the drive is based on recording information on hard, usually glass or aluminum plates, which are often coated with a magnetic material called chromium dioxide. Such drives are also called magnetic disks. For reference, we note that hard drives use 1 or 2 plates that are installed on the axis of the device.

1 . Volume, connection interface and hard disk rotation speed

The first thing a buyer of a hard drive pays attention to before purchasing a device is the capacity of the drive. If you look at least 10 years ago, then the amount of space in the internal memory of a hard drive of 50 gigabytes seemed to us simply unrealistic parameters. However, today such figures seem simply ridiculous to us, because not every game will be able to fit on such a drive. That is why it is extremely important to start the selection of a hard drive with the volume of the device, so that our purchase is profitable, and most importantly, effective.

As in any other segment of computer components, an interesting trend can be traced in the class of hard drives, which lies in the fact that premium models are an order of magnitude more expensive than competitors that are slightly inferior to them in terms of parameters. Paying for a device 3 times more expensive in order to feel like a satisfied owner of a beautiful toy for just a couple of days is a waste. On the contrary, you need to look closely at drives from the middle price segment. An example of a situation where we simply throw money away is the reality of life, where a 500 GB hard drive will not differ much in price from a 2 TB competitor. Dec Why save a couple of percent of the cost and buy a hard drive 4 times smaller in volume, only to be considered the owner of an elite brand?

Next, what you need to pay attention to when choosing a drive is the interface or connectors for connection. Almost any drive must be connected to the motherboard. This suggests that the device must also be somehow connected with all other components. This connection takes place using a special cable. There are 2 main types of cable for connection: the new format is SATA (ATA) and the already outdated one is IDE. In turn, the SATA format is divided into 3 types: SATA 1, SATA 2 and SATA 3.

We note right away that it is worth forgetting about cable formats such as SATA 1 and IDE forever, since they are simply no longer produced, and SATA 2 and SATA 3 differ only in data transfer speed. For example, SATA 2 transfers information at a speed of 3 gigabytes per second, and SATA 3 transfers files at a speed of 6 gigabytes per second, and both formats are currently fully up-to-date, that is, commercially available. In addition, it is worth knowing that the SATA 2 and SATA 3 cable formats are completely interchangeable. In the event that we select an external hard drive, then unambiguous preference should be given to an interface with the USB version 3.0 format.

Next, we move on to the next important parameter, such as the speed of rotation of the hard drive spindle. We all know from childhood that the faster the hard drive spindle rotates, the higher the read or write speed of the device will be. Therefore, do not forget about this indicator. To date, the spindle speed parameter has almost reached its maximum values ​​​​of 7200 rpm and most modern premium drives have just such an upper bar. However, there are devices with a speed of 10,000 revolutions per minute, but their cost will be simply cosmic. Thus, according to the spindle speed parameter, it is quite easy to select a hard drive, you just need to buy a device with the highest value in accordance with an adequate price.

It is also worth considering some of the nuances if we select a hard drive for a gaming computer. In this case, as experts recommend, it is better to focus on drives with a spindle speed of 10,000 rpm, and the best thing would be to buy a hard drive that is made using SSD technology, that is, high-performance solid-state devices. For reference, we note that the vast majority of external drives are implemented with a spindle speed of 5,400 rpm, and the most interesting thing is that they work no worse than faster ones.

2 . Buffer memory, dimensions and hard drive brand

Buffer memory is a cached space in which a certain amount of information is concentrated. Cached memory is information that has already been read from the hard disk, but not transferred through the connection interface. It is believed that the larger the amount of buffer memory, the better will be the performance and speed of the system as a whole. As for external drives, the optimal buffer memory parameter for them is 6-8 megabytes , however, this is not enough for an internal hard drive and requires at least 32 megabytes , and better 64 megabytes As the saying goes, more is better than less. This parameter will not greatly affect the final cost of the device, but it will definitely be noticeable on the speed of the computer.

When choosing an external or internal drive, it is also worth considering its dimensions, since sometimes drives with the same functionality have different sizes. The minimum form factor for a hard drive is 2.5 inches, and the optimal form factor for a device is 3.5 inches. As a rule, with the minimum size of the drive, such a parameter as the spindle speed has a lower indicator and is no more than 5400 rpm. By the way, for the sake of compactness, such drives are placed on laptops. As for large hard drives, they are installed on classic personal computers.

If we consider the selection of a device by manufacturer, then quite often in computer equipment stores we can see a huge number of different brands. However, all these brands are produced by only 2 large companies such as Seagate and Western Digital. As for the pros and cons of this or that manufacturer, based on the majority of reviews from experts and users, we managed to collect more negative information about Seagate. The drives of this company are less reliable. As they say, Seagate was once the best, but over time it “blew away”.

Also, do not forget that after buying a new hard drive, it needs to be given an increased load in order to check the device, so to speak, to create conditions close to stressful. This is done in order to reveal hidden defects of the device and have time to exchange it for another one under warranty. If the drive successfully passes such a test, then you can be almost 100 percent sure that the hard drive will serve us faithfully, and certainly not only the warranty period. Also, when choosing a particular drive model, it is necessary to clarify the information from the seller regarding the availability of service centers in our city, because the devices themselves are reliable, but there is always a certain percentage of probable breakdown.

WHAT IS SMART WATCH. FEATURES AND HOW TO CHOOSE

3 . External hard drive, as one of the varieties of hard disk

The parameters and functions of an external and internal hard drive are basically the same. However, if we consider the selection of an external drive by brand, then one more is added to the 2 main manufacturers - Transcend. The advantages of external drives are unambiguous - you do not need to install them in the system unit of a personal computer or in a laptop case. To install such a drive, you just need to connect it using a special cable that comes with the device to the appropriate computer connector. For reference, we note that preference should be given to the high-speed USB 3.0 interface. By the way, this interface is fully compatible with USB 2.0 and can be connected to any system without any problems.

As for the dimensions of external devices, they, like the parameters with functionality, are similar to internal drives. Note that if we choose an internal hard drive, then in principle you can ignore the dimensions, but for an external one they are important, since a compact device is always much more convenient to take with you. Therefore, it is better to buy an external drive with a size of 2.5 inches. Of course, the speed will definitely be lower than if we took it with a 3.5-inch form factor, but compactness for this type of gadget is simply priceless. When buying, you also need to pay attention to the strength and security of the device from mechanical influences. It is better to take an external drive in a rubberized case or with a case, because if an unprotected device is frequently accidentally dropped from a small height, for example, from 5-10 centimeters, they tend to break.

It is worth paying attention to modern external drives in the form of special boxes, which are gaining more and more popularity among users every day. These hard drive boxes have a direct USB-format connection to a computer. This is a big plus of the device, since almost all modern PC system units have a corresponding USB connector, which is very convenient when working with the device.

4 . Solid state drive SSD: features, dimensions, data transfer speed

Literally recently, SSD devices or solid-state storage devices began to be called a new format for drives. Such drives can hardly be called hard drives, they are more related to a large flash drive containing various microcircuits with boards. SSD drives differ from traditional HDD format hard drives in that they do not contain mechanical parts. Data transmission in such devices is carried out electronically. The drive is connected using SATA 2, SATA 3 or PCI Express interfaces. As experts in the field of computer technology recommend, it is better to choose SSD drives with a high-speed PCI Express interface, since the data transfer parameter will be many times faster than that of Satovsky.

In addition to innovative ways of functioning, such drives are much more compact than classic external hard drives and are sold on the market with a special adapter that comes with the device. The adapter is designed so that you can easily insert an SSD drive into the HDD slot. As for the durability and security of such devices, they are much more reliable than conventional external devices. Among the disadvantages of SSD drives, one can single out their high cost compared to competitors. On average, the price of an SSD gadget is 2-3 times higher than the cost of an HDD drive.

If we finally decide to buy an SSD drive, then it is better to consider models with a large capacity, at least 1 terabyte, since the price of such devices from a volume of 512 megabytes will differ very little in price. In addition, the large volume of the device will not greatly affect the speed of the operating system, but as experts recommend, if the operating system has not been updated for a long time, then it is better not to purchase drives in excess of 1 terabyte, or, as an option, before buying, install a new Windows OS latest version.

For reference, we note that the SSD media format during creation and production is not intended to store a large number of programs. It is best to store a couple of large applications or programs similar to the operating system on such a drive. As for small programs, if we have a large number of them, then it is better to store them on the HDD drive. In addition to ensuring the speed of the system and the reliable safety of information, thanks to such actions, we can also save a lot on the purchase of a particular drive, and all this thanks to the diversification of data storage on different media.

Video: What is a hard drive? Features, types, characteristics and how to choose”

In conclusion, we note that now that we know what types of drives for storing and transmitting information exist, it is worthwhile to understand that certain media formats that are currently sold in computer stores will function optimally only with the latest versions of operating systems. Therefore, you need to know that everyone's favorite old and good Windows XP, unfortunately, cannot be combined with the same SSD drives. In addition, you do not need to fully trust the sales consultants who are interested in selling this or that gadget to us. It is best to read reviews and recommendations on major computer forums and reviews before going to the store to buy a drive.

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Content

All computer software is stored on its hard drive. When you turn on the computer, it is one of the first computer nodes to turn on and one of the last to turn off. Any operations of reading and saving information, launching programs and applications, games, music, photo and video files of the user occur by accessing this device. A magnetic hard drive for a computer installed in a PC, server or laptop from different manufacturers must have a large volume, be reliable and provide the user with high-speed access to his information.

What is a computer hard drive

Winchester, screw - this is the name of a computer's permanent storage device, its main memory. Structurally, it is a parallelepiped 10-15 cm long, 7-10 cm wide, 0.7-3 cm thick. There are disks built into the case of a laptop or desktop computer, and external ones that are connected to the computer via a USB cable. When creating the first microcontrollers using a microprocessor, permanent memory devices were used on microcircuits, the erasure of information in which was carried out by ultraviolet irradiation.

The creation of a PC required the development of a device for fast recording, reading information. The first HDDs (Hard Disk Drives) were created by analogy with vinyl records - in the case there are several disks with a magnetic coating on a rotating spindle, a read and write head, working on the principle of a tape recorder's magnetic head, its positioning mechanism, and a communication interface with the motherboard. More recently, solid-state drives of large amounts of information SSD have appeared, which are replacing the HDD, but they are not yet very common due to the high cost.

HDD

The technology for the production of HDD drives on a hard magnetic disk for a computer has been improved for several decades. Now HDDs of 1 TB and above are widely used, the cost of which is from 3,000 rubles. Further growth of the memory capacity of magnetic storage devices is limited by their size and technological capabilities. Their serious disadvantage is the moving mechanical elements, due to which the entire device fails when shaken. HDDs are cheaper, which explains their popularity for regular home computers.

SSD

Magnetic HDDs had no alternative until 2009, when a new mass storage device, the Solid State Drive (SSD), was introduced. Based on the use of chips that can be located both on the motherboard and in a separate case, this type of drive has appeared in mass-produced children's computers from the Taiwanese company Quanta Computer since 2007 as flash memory. Then ASUS began to complete the line of netbooks of the EEE PC 700 series with SSD devices. The advantages of this technology are:

• silent work;
• high storage performance;
• small sizes;
• low power consumption.

SSHD

At the junction of two technologies - the old HDD and innovative SSD-memory, their hybrid appeared - SSHD (Solid State Hybrid Drive). It is a hard HDD, to which fast MLC flash memory is added to organize a fast and powerful cache for storing the operating system and frequently used programs by the user. The cache size is now set to 8 GB. When accessing a memory device, information is first searched in the cache, and only if it is absent, an access is made to the HDD-memory. The result of such hybridization is an increase in the speed of work by 30-40%.

hard drive rating

The speed of SSHD and SSD memory exceeds the speed of conventional magnetic media, but their cost is much higher. The best choice of a hard drive at the moment when equipping powerful or gaming computers is to install a small SSD device to install the operating system and frequently used programs and a large HDD to store all user information. As a compromise between these two technologies, it is possible to purchase a hybrid SSHD hard drive.

You can buy a hard drive for a computer in computer supermarkets in Moscow, St. Petersburg, and other Russian cities. Active Internet users, before making a purchase of a hard drive, can find out how much a hard drive costs, choose it in online stores by photo, order it for promotions, sales, discounts. With the current level of development of the service, the problem of delivery is not worth it at all - you just need to name the address when buying. Many stores have their own delivery services, use courier companies or deliver cheaper - by mail.

The main question will be to choose the right model.

western digital

Modern traditional HDDs with a memory capacity of 1 terabyte are offered at an affordable price for many users. This option from Western Digital has good technical characteristics:

• model name: WD10EACS;
• price: 7,600 rubles;
• characteristics: capacity - 1Tb, rotation speed - 7200 rpm, SATAII connector, form factor - 3.5, type - HDD;
• pluses: reliable mechanics;
• cons: not marked.

Under the Western Digital trademark, the entire range of components for computer equipment is produced. The presented HDD model is suitable for servers:

• model name: WD60EFRX;
• price: 13 440 rubles;
• characteristics: form factor - 3.5, capacity - 6 TB, SATA 6Gb / s interface;
• pluses: large amount of memory;
• cons: high cost.

Toshiba

Storing a large amount of important information requires the creation of its backup copies. For this purpose, an external Toshiba TM hard drive is suitable, with which you can not worry about data security:

• model name: Canvio Alu S3 2Tb Blue;
• price: 5 300 rubles;
• characteristics: capacity - 2 TB, form factor - 2.5", rotation speed - 5400 rpm, buffer memory - 8 MB, interface types - USB 2.0, USB 3.0;
• pluses: reliability and high performance;
• cons: not noticed.

Products of the Japanese company Toshiba are of high quality and careful selection of components. The presented model has a high resistance to mechanical stress - shock, shaking:

• model name: HDWD105EZSTA SATA-III 500Gb;
• price: 2 520 rubles;
• characteristics: form factor - 3.5", capacity - 500 GB, buffer memory - 64 MB, rotation speed - 7200 rpm, interface - SATA 6Gbit / s, transfer rate - 600 b / s, NCQ support, noise level - 26 dB, power consumption - 6.4 W, dimensions (WxHxD) - 101.6x26.1x147 mm, weight - 450 g;
• pluses: impact resistance during operation - 70 G;
• cons: not marked.

Seagate

One of the most common in Russia are Seagate hard drives. She offers to buy a BarraCuda HDD, which is suitable for any desktop computer:

• model name: ST1000DM010;
• price: 2,633 rubles;
• characteristics: capacity - 1 TB, form factor - 3.5, SATA 6Gb / s interface;
• pluses: good repair service for products of this company;
• cons: not marked.

An external HDD can be used not only for storing large amounts of information, but also for the fastest way to transfer it from one computer to another. The proposed TM model has a case in a restrained classic style:

• model name: Backup Plus Portable 4Tb Blue STDR4000901;
• price: 7 350 rubles;
• characteristics: capacity - 4 TB, USB 3.0 interface, data transfer rate - 120 Mb / s, dimensions (HxLxW) - 22.35x116.9x82.5 mm, weight - 307 g;
• pluses: large memory capacity;
• cons: expensive.

Samsung

Samsung has long been the leader in sales of computers and laptops in our country. The presented HDD of its production of the Spinpoint F3 line combines good technical characteristics and affordable cost:

• model name: Spinpoint F3 500Gb SATAII 3.5"(HD502HJ);
• price: 4 640 rubles;
• characteristics: memory capacity - 500 GB, form factor - HDD 3.5", shock resistance during operation - 70 G, average access time - 8.9 ms, buffer memory - 16 MB, connection - SATA 3Gbit / s, rotation speed - 7200 rpm , operating noise level - 28 dB;
• pluses: high speed of rotation of a spindle;
• cons: not noticed.

The presented model has a small amount of memory by modern standards. But, given its low price and good speed, it will interest many users of older computers:

• model name: SP0411N 40 Gb 7200 rpm IDE 3.5" HDD;
• price: 1,700 rubles;
• characteristics: size - 40 Gb, rotation speed - 7200 rpm, IDE connector, form factor - 3.5, buffer memory - 2 Mb;
• pluses: suitable for replacing HDD with IDE interface cables;
• cons: only suitable for IDE interface.

Lenovo

Over the past few years, the products of the Chinese manufacturer Lenovo have become popular among our population. We present the version of this company of the most demanded volume for home PCs:

• model name: Caviar Blue WD1600AAJS-08PSA0;
• price: 5 220 rubles;
• characteristics: form factor - HDD 3.5, memory - 160 GB, buffer - 8 MB, rotation speed - 7200 rpm, SATAII interface;
• pluses: high spindle speed;
• cons: not marked.

Lenovo produces a wide range of products - smartphones, computers, accessories. The proposed device is intended for use in server systems, has a SAS 3.0 (12Gb/s) connection interface and a rotation speed of 10000 rpm:

• model name: 00NA251;
• price: 45 867 rubles;
• characteristics: form factor - 2.5, capacity - 900 GB, buffer - 32 MB, rotation speed - 10000 rpm, data transfer rate - up to 1200 MB / s, interface - SAS, weight - 400 g;
• pluses: high-speed hard drive;
• cons: high cost of the device.

Sony

Leading computer hardware manufacturers innovate in their products before many other companies. Sony HDD is ideal for backing up and archiving large amounts of data:

• model name: LTX2500GN 6.25Tb / 3Tb native;
• price: 2 694 rubles;
• characteristics: form factor - tape media, capacity - 3 TB, transfer rate - 160 MB / s without compression, 400 MB / s with data compression, dimensions - 105x22x102 mm, weight - 275 g;
• pluses: high speed of data search;
• cons: not marked.

External drives are used to store information, the large size of their memory makes it possible to download a lot of movies and series to watch on TV. Presented TM SONY hard drive produces data encryption and has password protection for the security of your data:

• model name: HD-SL1;
• price: 7 200 rubles;
• characteristics: weight - 190 g, dimensions - (HxWxD) 81x12x118 mm, interface - USB 3.0, memory -1 TB;
• pluses: compactness, stylish design, silver coating;
• cons: not noticed.

How to choose a hard drive for your computer

When deciding which hard drive is better to buy for a computer, you need to find an acceptable balance of its volume, speed and cost between HDD, SSHD and SSD devices. Before buying a hard drive, there are a few basic criteria to consider:

• the geometric dimensions or form factor indicate a size of 3.5 inches for desktops and 2.5 inches for laptop internal hard drives;
• disk volume is an important parameter that directly affects its cost;
• type of interface - previously IDE standard cables were used, now the most common format for PCs is SATA and SAS for servers;
• read / write speed for SATA drives is in the range from 130 to 180 Mb / s;
• the spindle speed in modern models of home PCs is 5200-7200 rpm, for servers it reaches 10000 rpm, this characteristic is not at all relevant for SSDs;
• cache size becomes especially important for hybrid drives.

Volume

The current minimum hard disk capacity when using modern HDD models is about 200 GB. The most optimal volume, popular for ordinary PC users, are 500 GB models. Computers for commercial purposes are offered with storage capacities from 1 TB. Please note that the BIOS (Basic input-output system - Basic input-output system) is available to determine the HDD with a size of no more than 2 GB. Therefore, the use of devices with a capacity of more than 2 GB will require the use of the UEFI interface, which is supported by many motherboards.

Speed

For a modern computer, a hard disk write / read speed of 150-200 Mb / s is enough for most users. This value is directly affected by the speed of disk rotation. The most common for standard PCs are 7200 rpm. The choice of hard drives with a speed of less than 5400 rpm is undesirable. SSD drives are currently showing the highest speed. They use two interfaces to connect to the motherboard - SATA and ePCI. For SATA, the read/write speed is up to 600MB/s, using the ePCI standard, it can be increased to 1GB/s.

One of the important characteristics of a file ROM is the type of connectors or interface. Old conventional HDDs used wide IDE interface cables that were used to connect all desktop PC nodes. Modern data interface standards are SATAI, SATAII and SATAIII. They differ in connectors on the motherboard, bandwidth, which for SATAIII is up to 6 Gb / s. Promising models of SSD drives use SATA and ePCI interfaces.

During computer startup, a set of firmware stored in the BIOS chip checks the hardware. If everything is in order, it transfers control to the operating system loader. Then the OS loads and you start using the computer. At the same time, where was the operating system stored before turning on the computer? How did your essay that you wrote all night stay intact after turning off the power of the PC? Again, where is it kept?

Okay, maybe I've gone too far and you all know very well that computer data is stored on a hard drive. Nevertheless, not everyone knows what it is and how it works, and since you are here, we conclude that we would like to know. Well, let's find out!

By tradition, let's look at the definition of a hard drive on Wikipedia:

HDD (screw, hard drive, hard disk drive, HDD, HDD, HMDD) is a random access storage device based on the principle of magnetic recording.

They are used in the vast majority of computers, as well as separately connected devices for storing backup copies of data, as file storage, etc.

Let's figure it out a little. I like the term hard disk drive ". These five words convey the whole point. HDD is a device whose purpose is to store data recorded on it for a long time. HDDs are based on hard (aluminum) disks with a special coating, on which information is recorded using special heads.

I will not consider in detail the recording process itself - in fact, this is the physics of the last grades of the school, and I am sure you have no desire to delve into this, and the article is not about that at all.

Also note the phrase: random access ” which, roughly speaking, means that we (computer) can read information from any section of the railway at any time.

It is important that the HDD memory is not volatile, that is, it does not matter whether the power is connected or not, the information recorded on the device will not disappear anywhere. This is an important difference between a computer's permanent memory and temporary ().

Looking at a computer hard drive in real life, you will not see any disks or heads, since all this is hidden in a sealed enclosure (hermetic zone). Externally, the hard drive looks like this:

Why does a computer need a hard drive?

Consider what an HDD is in a computer, that is, what role it plays in a PC. It is clear that it stores data, but how and what. Here we highlight the following functions of HDD:

• Storage of OS, user software and their settings;
• Storage of user files: music, video, images, documents, etc.;
• Using part of the hard disk space to store data that does not fit in RAM (paging file) or storing the contents of RAM while using sleep mode;

As you can see, a computer hard drive is not just a dump of photos, music and videos. It stores the entire operating system, and in addition, the hard drive helps to cope with the workload of RAM, taking on some of its functions.

What is a hard drive made of?

We partially mentioned the components of the hard drive, now we will deal with this in more detail. So, the main components of the HDD:

• Frame Protects hard drive mechanisms from dust and moisture. As a rule, it is airtight so that the same moisture and dust do not get inside;
• Disks (pancakes) - plates made of a certain metal alloy, coated on both sides, on which data is recorded. The number of plates can be different - from one (in budget options) to several;
• Engine - on the spindle of which pancakes are fixed;
• Head block - a design of interconnected levers (rocker arms), and heads. The part of a hard drive that reads and writes information to it. For one pancake, a pair of heads is used, since both the upper and lower parts of it are working;
• Positioning device (actuator ) - a mechanism that drives the block of heads. Consists of a pair of permanent neodymium magnets and a coil located at the end of the head unit;
• Controller - an electronic microcircuit that controls the operation of the HDD;
• parking zone - a place inside the hard drive next to the disks or on their inside, where the heads are lowered (parked) during downtime, so as not to damage the working surface of the pancakes.

Such a simple hard drive device. It was formed many years ago, and no fundamental changes have been made to it for a long time. And we move on.

How a hard drive works

After power is supplied to the HDD, the engine, on the spindle of which the pancakes are fixed, begins to spin up. Having gained a speed at which a constant stream of air is formed near the surface of the discs, the heads begin to move.

This sequence (first the discs spin up, and then the heads start working) is necessary so that the heads hover over the plates due to the resulting air flow. Yes, they never touch the surface of the disks, otherwise the latter would be instantly damaged. However, the distance from the surface of the magnetic platters to the heads is so small (~10 nm) that you cannot see it with the naked eye.

After starting, first of all, service information about the state of the hard disk and other necessary information about it, located on the so-called zero track, is read. Only then does the work with the data begin.

Information on the computer's hard drive is recorded on tracks, which, in turn, are divided into sectors (such a pizza cut into pieces). To write files, several sectors are combined into a cluster, which is the smallest place where a file can be written.

In addition to such a "horizontal" partitioning of the disk, there is also a conditional "vertical" one. Since all heads are combined, they are always positioned over the same track number, each over its own disc. Thus, during the operation of the HDD, the heads, as it were, draw a cylinder:

While the HDD is working, in fact, it performs two commands: reading and writing. When it is necessary to execute a write command, the area on the disk where it will be performed is calculated, then the heads are positioned and, in fact, the command is executed. The result is then checked. In addition to writing data directly to disk, information also ends up in its cache.

If the controller receives a read command, first of all, it checks for the presence of the required information in the cache. If it is not there, the coordinates for positioning the heads are calculated again, then the heads are positioned and read the data.

After completion of the work, when the power supply of the hard drive disappears, the heads are automatically parked in the parking zone.

This is how a computer hard drive works in general terms. In reality, everything is much more complicated, but the average user, most likely, does not need such details, so we will finish this section and move on.

Types of hard drives and their manufacturers

Today, there are actually three main manufacturers of hard drives on the market: Western Digital (WD), Toshiba, Seagate. They fully cover the demand for devices of all types and requirements. The rest of the companies either went bankrupt, or were taken over by someone from the main three, or re-profiled.

If we talk about the types of HDD, they can be divided in this way:

1. For laptops, the main parameter is the device size of 2.5 inches. This allows them to be compactly placed in the laptop case;
2. For PC - in this case, it is also possible to use 2.5 ″ hard drives, but as a rule, 3.5 inches are used;
3. External hard drives are devices that are separately connected to a PC / laptop, most often acting as file storage.

There is also a special type of hard drives - for servers. They are identical to conventional PCs, but may differ in interfaces for connection, and greater performance.

All other divisions of HDD into types come from their characteristics, so we will consider them.

Hard drive specifications

So, the main characteristics of a computer hard drive:

• Volume - an indicator of the maximum possible amount of data that can be accommodated on the disk. The first thing they usually look at when choosing an HDD. This figure can reach 10 TB, although 500 GB - 1 TB is more often chosen for a home PC;
• Form factor - the size of the hard drive. The most common are 3.5 and 2.5 inches. As mentioned above, 2.5″ in most cases are installed in laptops. They are also used in external HDDs. 3.5″ is installed on the PC and on the server. The form factor also affects the volume, as more data can fit on a larger disk;
• Spindle speed - How fast do pancakes rotate? The most common are 4200, 5400, 7200 and 10000 rpm. This characteristic directly affects the performance, as well as the price of the device. The higher the speed, the greater both values;
• Interface - method (connector type) of connecting the HDD to the computer. The most popular interface for internal hard drives today is SATA (older computers used IDE). External hard drives are usually connected via USB or FireWire. In addition to those listed, there are other interfaces such as SCSI, SAS;
• Buffer volume (cache memory) - a type of fast memory (by type of RAM) installed on the HDD controller, designed for temporary storage of data that is most often accessed. The buffer size can be 16, 32 or 64 MB;
• Random access time - the time during which the HDD is guaranteed to write or read from any part of the disk. It fluctuates from 3 to 15 ms;

In addition to the above characteristics, you can also find indicators such as.

The various types of hardware produced today depend primarily on the type of computer they are designed for.

The main factors that determine the physical and technical characteristics of a hard disk are the amount of physically available space on the computer, the speed required for data transfer and the amount of disk space required. PATA, SATA, SCSI, and SSD hard drive types are the most commonly used in today's computers.

This is a type of hard drive with a parallel interface. These types of drives are also known as Integrated Drive Electronics (IDE) and Enhanced Integrated Drive Electronics (EIDE). The labels refer to the type of interface that is used to connect the drive to the CPU board. These drives use either a 40 or 80 wire cable with a wide 40 pin connector. 40-core cables are used for older and slower hard drives, while 80-core cables are used for newer and faster drives.

Currently, PATA hard drives have almost completely been replaced by SATA hard drives.

This is a type of hard drive with a serial interface. These drives use a completely different connector than their PATA counterparts. They also use a different non-IDE power adapter, although adapters are readily available. The main difference between SATA and PATA is that the former is thinner and supposedly has a faster data transfer interface than the latter. However, the speed of the PATA and SATA drives themselves is indistinguishable, and have the same RPM rating. But SATA drives are more efficient and consume less power.

Translated as "Small Computer System Interface". These hard drives are similar to IDE drives. They also spin at a higher speed than IDE, SATA, etc. IDE and SATA drives spin at 7200 rpm, while SCSI speeds from 10,000 to 15,000 rpm. Today, 10,000 RPM SATA drives are also manufactured. The higher the rotation speed, the faster the data is accessed, but it can also lead to a quick breakdown. SCSI hard drives need a controller that manages the interface between the drives and the computer's motherboard.

These hard drives, unlike other types, do not have moving parts. Typical hard drives consist of a spinning magnetic disk that performs the function of storing data, while SSDs use semiconductors for this purpose. Because they don't have any moving parts, these hard drives are much faster and less likely to fail than other hard drives. However, their price is slightly higher than other hard drives.

These were some of the types of hard drives commonly included in desktops and laptops. I hope this article was helpful to you.

In the distant fifties of the last century, or rather in 1956, IBM created the great-great-great-grandfather of modern information storage. This miracle weighed a little more than a ton (!) And contained only 5 megabytes of data. Such a "box" could only be lifted with a forklift.

As time went on, miniaturization replaced gigantomania. And now small "boxes" weighing a couple of hundred grams or even less can easily be placed in your system units, laptops, tablets and even phones, and recently in watches. It is believed that if aviation developed as rapidly as computers, today everyone could have a private plane at a price no more than a car. But back to the hardware.

When size matters

Miniaturization made it possible to create devices that fit in a matchbox and at the same time have a fantastic capacity.

Among all the sizes of hard drives, three groups can be conditionally distinguished

3.5 inches is the most common option, a resident of almost every desktop PC;
- 2.5 inches - a fellow in terms of information, but for laptops;
- 1-1.5 inches - usually placed on smartphones, MP3 players and similar devices.

But even despite the size, today a 1-inch "baby" is able to store hundreds of tracks of your favorite music and dozens of movies.

His majesty is the controller

If, upon opening the system unit, you find completely different connectors that you expected, there is a reason for that. Each controller has its own characteristics.

Hard drives differ in the way they are connected, as well as the principle of operation on:

IDE is the most widely used disk controller ever. Now it is not so often used. It allowed to develop a disk rotation speed of up to 7.5 thousand revolutions per minute, which gave good performance.
- SATA (I, II, III) - the next generation after IDE. With the best rotation speed, up to 10 thousand revolutions per minute.
- SCSI - has always stood somewhat apart, since it was not available to ordinary mortals. It differed in reading speed (up to 15 thousand revolutions), therefore it was used and is still used where special performance is needed.
- SDD - hard disk controller, designed on the principle of flash memory. It does not contain moving parts, everything inside is replaced with electronic components. Thanks to this, it offers high rates of MTBF (up to 1 million hours) and reading. However, today they are still expensive. As an alternative - a hybrid version with flash memory and a mechanical part.

Outside or inside?

You can point to another sign of the hard drive - the way it is placed. There are internal and external models.

The internal ones are quietly placed in the system unit, smartphone, and their work is visible only by the flashing of the lights outside.

External hard drives are small boxes with cords. Plugs into a USB port and works great. If you take such a box and disassemble it, then the same ordinary 2-5 or 3-5 inch HDD or SDD will appear.

And then what?

Progress has one very useful feature. He doesn't stand still. Methods for storing information using lasers, crystals, holographic images are already being developed. Various materials are being tested, innovative devices are being created. Perhaps soon the hard drives familiar to us will give way to a miracle that has descended to us from the pages of books in the Sci-Fi genre.