What is a hard drive? Hard drive - what is it? Features of hard drives. Possibility of connection to TV

There are different types of disks: hard, local, CD, DVD, etc. Understanding the purpose of each of them on your own is difficult, but necessary. Because the age of technology requires it. So, what is the disk for?

HDD

HDD is in system unit computer. What is a hard drive for in a computer? The hard drive stores all information, the operating system and all programs. On the computer we see the information that is stored on the hard drive in the “My Computer” item: “Local Disk C”, “Local Disk D”.

Local disks

The hard drive is divided into sections: “Local Disk C” and “Local Disk D”. You can store programs, files, movies, music, etc. on disks. But, if there is a C drive, why do we need a D drive? The point is that if damaged operating system malware, all files are damaged. To establish normal work computer, you have to reinstall the operating system. Everything that was stored on local disk C, cannot be restored. That’s why you need disk D; the information can be saved on it if you reinstall the OS. It is recommended to store the most important items on drive D important files and archives to avoid the risk of losing these documents.

CD, DVD, blu ray and more

All of the above are completely material things, unlike local disks. These discs are made in the form of a plastic disc with a hole in the center. To determine what the above disks are needed for, you need to understand them separately.

CD - compact discs. There are two types of CD-R, which can be used to record information only once, and CD-RW, which can be used to record information on which can be written several times. Memory capacity up to 900 MB (90 minutes of recording).

DVDs are digital multi-purpose discs. There are three types: DVD-R, DVD-RW, DVD-RAM. The purpose of such disks is very simple. They are needed to store information: audio, video High Quality, various files and documents. DVD-R cannot be rewritten at all. DVD-RW can be rewritten up to 1000 times. DVD-RAM can even be rewritten up to 100 thousand. once. Capacity DVDs 17 GB. DVDs are more reliable than CDs.

Blu Ray (BD) - optical discs relatively new standard. Such disks are needed to store large amounts of information (the most common volume is up to 50 GB), including storing high-quality audio and video. Rarely, there are BD discs with a capacity of up to 320 GB. They are also divided into several types: BD-R, on which you can record information once, BD-RE, you can record information multiple times, BD-RE DL, you can record information up to 50 GB multiple times.

Cleaning disc

A cleaning disc is needed to clean the lenses of various players and disc drives. And this, in turn, is necessary so that the disks do not “slow down” and viewing information from them does not turn into a very difficult process. The cleaning disc is sold complete with cleaning liquid; the disc itself has a brush.

Why do you need a driver disk?

These discs contain software, by installing it on your computer, you can access hardware the device for which this driver is intended (web camera, scanner, camera).

When the computer starts, a set of firmware stored in BIOS chip, checks equipment. If everything is fine, it transfers control to the operating system boot 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, which you wrote all night, remain intact after the PC was turned off? Again, where is it stored?

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

What is a hard drive

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

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

Used in the vast majority of computers, and also as separately connected storage devices backup copies data as file storage and so on.

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

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

Let us also pay attention to the phrase: “ random access “Which, roughly speaking, means that we (the computer) can read information from any section of the railway at any time.

An important fact is that the HDD memory is not volatile, that is, no matter whether the power is connected or not, the information recorded on the device will not disappear anywhere. This important difference permanent computer memory, from temporary ().

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

Why does a computer need a hard drive?

Let's look at what a 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 the HDD:

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

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

What does a hard drive consist of?

We partially mentioned the components of a hard drive, now we will look at 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 sealed so that moisture and dust do not get inside;
Discs (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 the pancakes are fixed;
Head block - a design of interconnected levers (rocker arms) and heads. The part of the 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 are working;
Positioning device (actuator ) - a mechanism that drives the head block. Consists of a pair of permanent neodymium magnets and a coil located at the end of the head block;
Controller — electronic chip work manager HDD;
Parking zone - a place inside the hard drive next to the disks or on their inner part, where the heads are lowered (parked) during downtime, so as not to damage the working surface of the pancakes.

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

How does a hard drive work?

After power is supplied to the HDD, the motor, on the spindle of which the pancakes are attached, begins to spin up. Having reached the speed at which a constant flow of air is formed at the surface of the disks, the heads begin to move.

This sequence (first the disks spin up, and then the heads start working) is necessary so that, due to the resulting air flow, the heads float above the plates. 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 plates to the heads is so small (~10 nm) that you cannot see it with the naked eye.

After startup, first of all, service information about state of rigid disk and others necessary information about him, located on the so-called zero track. Only then does work with the data begin.

Information on a computer's hard drive is recorded on tracks, which, in turn, are divided into sectors (like 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 this “horizontal” disk partition, there is also a conventional “vertical” partition. Since all the heads are combined, they are always positioned above the same track number, each above its own disk. Thus, during HDD operation the heads seem to draw a cylinder:

While the HDD is running, it essentially performs two commands: read and write. 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 the disk, the information also ends up in its cache.

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

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

Like this in general outline and the computer hard drive is working. In reality, everything is much more complicated, but ordinary user, most likely, such details are not needed, so let's finish this section and move on.

Types of hard drives and their manufacturers

Today, there are actually three main manufacturers on the market hard drives: 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, were absorbed by one of the main three, or were repurposed.

If speak about types of HDD, they can be divided this way:

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

There is also a special hard type disks - for servers. They are identical to regular PC ones, but may differ in connection interfaces and greater performance.

All other divisions of HDD into types come from their characteristics, so let’s 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 stored on the disk. The first thing they usually look at when choosing HDD. This indicator can reach 10 TB, although for a home PC they often choose 500 GB - 1 TB;
Form factor — size of the hard disk. 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 in PCs and servers. The form factor also affects the volume, since larger disk can fit more data;
Spindle speed — at what speed do the 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) HDD connections 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 also such interfaces as SCSI, SAS;
Buffer volume (cache memory) - type fast memory(type of RAM) hard drive installed on the 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. Ranges from 3 to 15 ms;

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

Greetings, dear readers, guests and simply interested visitors! Today I want to answer a question that is difficult for many users - why do you need a hard drive? The fact is that if the purpose of many devices is clear even from the name, then in the case of hard drive This question comes up often.

What it is? What are its functions? What does it look like and where can I find it on the system unit? How to choose it? Saw interest Ask higher? Sit back, now you will get answers to everything!

Hard drive - why not soft?

A hard drive (other names - hard drive, hard drive) is a compact device in the system unit that is connected to small cables (wires). Its purpose is to store absolutely all user information. This includes basic programs such as the operating system, settings files, and other computer controls. In addition, the hard drive stores everything that the user downloads onto it.

Games, music, movies, photographs, books - all this is located on millions of clusters inside the device itself.
A hard drive is so called because inside its powerful and durable case there are hidden metal plates on which, in fact, all information is recorded.

And many years earlier, data was stored on thin plastic sheets coated with magnetic coating. They, quite logically, easily bent and broke.

Now these are not used anywhere due to their fragility, unreliability and absolute irrelevance. Ordinary hard drives have completely supplanted them not only from system units, but even from people’s consciousness. Nowadays few people remember floppy disks for storing data, they are excellently replaced by CDs and DVDs, flash drives.

Types of hard drives

All currently existing hard drives differ from each other in many parameters; below I will present to your attention the most important of them. If you take a closer look at them and understand what you need, it’s easy to decide which one to choose and how:

Connection interface

There are several options - IDE and SATA. While the connector for the latter can still be found on older modifications of motherboards, IDE is almost never found anywhere. Replaced both of them new interface, called SATA 2. The plug through which the hard drive is connected to the board is literally 1 cm long and 2-3 mm wide (the wire itself is dark pink or red). For comparison: the IDE connector is a giant cable 4-5 cm long. It can easily be accidentally bent and, as a result, broken.

There are also SSD hard drives. There are no disks in them, there are no moving elements at all. They work on the principle of regular flash drives, but with much more memory. It should be borne in mind that such disks work much faster than classic hard drives. But with equal amounts of memory, their price is several times higher than that of HDDs.
And if you wish, you can purchase and use external hard disk. There are no problems at all - just select the required amount of memory and connect via USB.

Storage capacity

Previously, all the information on a computer could fit on one small floppy disk, but digital age destroyed this standard. Now the minimum volume that can be found is 80 GB. This space is enough for about 5-6 modern games or 30-40 films per good quality. There is no talk about music and files like MS Word and Excel, since they can be recorded in thousands.
If you plan to handle a large amount of information, then the best option you will have a hard drive with 500 GB or more.

Data transfer rate

Important indicator. Extremely important for those who want fast work no brakes. The higher this speed, the faster the hard drive will exchange information with the system so that it displays it on the monitor.

Energy consumption

You need to pay attention to this indicator if you are taking a device for a laptop, as this will save battery power.
There are other characteristics, but few people are interested in them. These include impact resistance, noise level and others.

Connecting a drive

After choosing, many users begin to think about how to properly connect the hard drive. In fact, this is a very simple process. Simply insert it into the designated slot (the bottom part is located directly behind the front panel) and screw it tightly. Next, you need to insert the wire included in the kit into the corresponding connector on motherboard and directly into the hard drive itself. That's it, the connection process is complete.

Another question is connecting the fan (cooler). It is mounted directly on the hard drive and connected to another port on the motherboard. On each model this connector is located in different places, so you need to look for the specific point in the user manual.

I think that I have given a comprehensive answer to the question about the need for a hard drive and the criteria for choosing it for a laptop. If you think that the material was useful, share it with your friends on social networks. Who knows, maybe this will make the choice easier for them too!

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HDD, HDD or Winchester– a storage device for permanent storage of information based on the principle of magnetic recording. HDD stands for Hard Disk Drive, hence the name - hard: inside the device body there are disks made of metal or glass, on which magnetic coating is applied. It is on this layer that the data is written.

On the market today HDD format 3.5 inches are presented very widely, and there is a variety not only in the volume of hard drives, but also in the speed of their operation, internal structure, type. It’s worth understanding these parameters to understand which hard drive is better to purchase.

Device and types of hard drives

As mentioned above, a hard drive is designed for permanent storage of information, and the difference between its memory and RAM is that it is non-volatile - that is, it is stored on the media when the power is turned off. A hard drive is an electromechanical device, meaning it has moving parts, and consists of several main parts.

This integrated circuit, which controls the writing/reading processes and disk operation. It is installed on top of the main drive body. The heart of the hard drive is hidden in the case itself, consisting of a spindle (electric motor) that rotates the disk; the reading head (rocker arm), which is movable and reads information directly from the surface of the media, and the magnetic memory disks themselves (there may be different quantities, they are located one above the other, in layers).

There are three types of hard drives currently common on the market:

Expensive HDD models may differ from cheap ones with the same volume precisely in the data transfer speed; it will be noticeably higher due to many factors: the cache memory may be better optimized, the electro-mechanical unit is organized differently, a different number of magnetic disks for the same volume. Also often expensive wheels more reliable and resistant to external influences.

Data transfer speed is the combined result of all other parameters and technologies used in the disk, therefore, if your choice depends mainly on the disk speed, then it is convenient to navigate according to it. The faster the drive, the more expensive it will be.

What volume should I choose?

· 250 - 500 GB– it’s worth choosing how a budget option, or to an office PC when you do not need a large amount of storage space for media files. However, there is enough space to install programs and systems. Also small volume, in the case of a high-speed model, can be used exclusively for installing the operating system, and the data can be stored on a slower disk with a larger capacity.
· 1 TB - 4 TB- this volume is suitable for home computer, enough to store a large collection of movies in HD resolution. A minimum of 1 TB is now standard for the average user.
· 5 - 10 TB – maximum volume for hard magnetic disks today. It will cost you quite a lot, and is most likely necessary when working with large volumes of files, for example, during professional editing. Alternatively, create RAID array of the same volume from 1-2 TB disks, which will increase speed.

What else should you pay attention to?

· Optimization for RAID array. You will need it if you want to create an array of several disks. The point is that instead of several separate disks the system begins to see one united, which is different types array increases speed or reliability. Definitely worth choosing if you need maximum reliability or maximum speed in the array.

Why do you have to buy new hard disk? Everyone may have their own reasons, but basically this means that the speed and loading of programs has noticeably decreased, or there is not enough space for recording new information on computer.

Hard drives are either internal, which are installed in a computer, or external. Internal ones come in regular sizes (3.5” for computers) and for laptops (2.5” form factor). This article will focus specifically on internal drives. Let's sort it out real example disk selection. After all, a sudden and rash decision can lead to new HDD will not satisfy your needs.

Hard disk capacity

Disks with 40 or 80GB of memory are a thing of the past. Now on the market, hard drive capacity is measured in hundreds of gigabytes and terabytes. What disk size should I choose? A lot depends on what kind of work is being done on the computer and how much space you actually need. You have to pay for more volume. It is better to proceed from real needs with a 20-50% margin.

Considering that hard drives with a capacity of less than 500GB can no longer be found in stores, we will assume that this is the minimum sufficient volume. So much space is enough for an ordinary home use, for work and leisure. If you need to download large amounts of information from the Internet, such as torrents, and if you install heavy games, then take a disk with a capacity of 1TB or more. Discs more bigger size will be useful to those who store data archives. Well, in general, they themselves know why they need such a disk

People sometimes ask me how many megabytes are in 1 gigabyte, or how many gigabytes are in a terabyte. Everything here is simple, but with a twist. In fact, there are 1024 bytes in one kilobyte, i.e. 1K=1024B. There are 1024 kilobytes in one megabyte, 1024 megabytes in one gigabyte, and 1024 gigabytes in one terabyte. But manufacturers of hard disks went on a little trick and took the number 1000 rather than 1024 as a multiplier, supposedly so that buyers would not be confused

Yeah, cool! Only now, having installed a drive with a capacity of, say, 500GB, we will see only 465GB available! Because the computer still counts gigabytes as expected!

This is such an embarrassment, so there is no need to rush to give the hard drive back to the store. I would like to warn you against purchasing a disk with a capacity larger than 2TB. If you have an old motherboard running a regular BIOS, then you still won’t see more than 2TB! Such models require UEFI instead of BIOS. To check this, carefully read its interface and settings in the “Boot” menu. If you see the word “UEFI,” then consider yourself lucky. Or just read the instructions for your computer’s motherboard.

But is everything limited by disk space? No, there's another one important point- speed.

Hard disk speed

A disk with a large capacity does not guarantee fast loading programs. It just allows you to accommodate more information. Although, in principle, capacity also indirectly affects speed. Because the larger the volume, the higher the recording density, and, accordingly, it takes less time to read a data block. Simply put, a larger disk will almost always be faster than a smaller disk, all other things being equal.

Disk performance is measured by read/write speed in megabytes per second and data access time. Today you can find hard drives with speeds of 150-200MB/sec or more. Before choosing a hard drive, it is better to immediately decide on the issue of sufficient speed, because how to work with a disk on high speed very comfortable. Programs such as video or image editors, e.g. heavy enough for the system, with insufficient speed The disks will run slower, and the response to each operation will increase.

You can check the speed of an existing disk yourself. HD Tune Pro is a good program for this. For example, here is my old man's test

As a rule, the real read/write speed in megabytes per second is not written in stores. This parameter can be determined by tests on the Internet. Just search in Yandex or Google keywords with the disk model and the word “testing” or “review”. Among the search results you need to find tests, reviews or comparative analyzes this model with others hard drives. But they publish data access times, but I don’t recommend relying on information from manufacturers; it’s better to still look real reviews in the Internet.