Hello! Finally I found the time to please you with new material! I apologize for not writing for so long. The fact is that I was working on one project, which I will talk about in the future (subscribe to blog updates).
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 to write new information to the computer. Whatever the reason for the purchase new hard disk, everyone has something to think about before making a purchase. So let's figure it out how to choose hard drive for your computer and what you need to consider before purchasing. Below we will look at a real example of a purchase. hard drive. After all, a sudden and thoughtless decision may lead to the fact that the new HDD will not satisfy your needs.
How to choose a hard drive for your 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.
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. For more volume you have to pay more. It's better to base your actual needs with a 20-50% margin, rather than how much disk space your friend or neighbor has installed, since he may actually need a lot of space.
Considering that hard drives with a capacity of less than 500GB you will no longer find in stores, we will assume that this is the minimum sufficient volume. This amount of space is enough for normal home use, for work and for 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. Even larger disks will be useful for those who store large 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 joke. 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 hard drive manufacturers used a little trick and took the number 1000 rather than 1024 as a multiplier, supposedly so that buyers would not get 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 you don’t have to run to give the hard drive back to the store, because now you know how many megabytes are in one gigabyte.
I think it’s clear how to choose a hard drive by capacity, but I would like to warn you against buying a drive with a capacity larger than 2TB. If your motherboard is 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 motherboard computer.
But is everything limited by disk space? No, there's another one important point- speed.
Hard drive speed
A disk with a large capacity does not guarantee fast loading of programs. It just allows you to contain more information. The speed of loading programs and their execution is determined by the speed of the hard drive itself. 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 large disk will almost always be faster than a smaller disk, all other things being equal.
This article will only talk about hard drives(HDD) that is, about media on magnetic disks. The next article will be about SSDs.
What is a hard drive
By tradition, let's look at the definition of a hard drive on Wikipedia:
A hard drive (screw, hard drive, hard disk drive, 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, etc.
Let's figure it out a little. I like the term "hard disk drive". These five words convey the essence. HDD is a device whose purpose long time store the data recorded on it. 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’s 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 is an important difference between the computer's permanent memory and temporary memory (RAM).
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.
I think you understand what HDD is. Let's move on.
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 RAM while using sleep mode;
- As you can see, a computer’s hard drive is not just a dump of photos, music and videos. It stores everything operating system, and in addition to this, the hard drive helps cope with the workload of 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:
- Housing - protects the hard drive mechanisms from dust and moisture. As a rule, it is sealed so that 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), up to several;
- Engine - on the spindle of which the pancakes are fixed;
- Head block - a structure 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 actuates 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 area - a place inside the hard drive next to the disks or on their inner part, where the heads are lowered (parked) during idle time, 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, the first thing to do is read official information O state of rigid disk and other necessary information about it, 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 the average user most likely does not need such details, so let’s finish this section and move on.
Types of hard drives and their manufacturers
Today, there are actually three main hard drive manufacturers on the market: Western Digital(WD), Toshiba, Seagate. They fully cover the demand for devices of all types and requirements. The remaining companies either went bankrupt, were absorbed by one of the main three, or were repurposed.
If we talk about the types of HDD, they can be divided as follows:
1. For laptops, the main parameter is the device size of 2.5 inches. This allows them to be compactly placed in the laptop body;
2. For a PC - in this case it is also possible to use 2.5″ hard drives, but as a rule, 3.5″ are used;
3. External hard drives- devices that are separately connected to a PC/laptop, most often serving as file storage.
There is also a special type of hard drive - 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 is an indicator of the maximum possible amount of data that can be stored on a disk. The first thing they usually look at when choosing a HDD. This figure can reach 10 TB, although for a home PC they often choose 500 GB - 1 TB;
- 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 in PCs and servers. The form factor also affects the volume, since a larger disk can fit more data;
- Spindle rotation speed - at what speed 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) 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 also such interfaces as SCSI, SAS;
- Buffer capacity (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 is 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:
Data transfer rate;
- Number of I/O operations per second;
- Noise level;
- Reliability;
- Impact resistance, etc.;
That's all about HDD characteristics.
Hard drive - a component of any computer that contains data. Every computer must have at least one installed hard drive for storage operating system, programs and other user information. This disk is usually internal, or built into the computer, but since computer systems have evolved and there are different needs, threats from the Internet have appeared and different circumstances have arisen, so external hard drives are becoming increasingly popular. As a rule, external hard drives used in addition to the existing internal hard drive to store data. They also allow the user to set privacy or otherwise important information on them, then turn them off and store them in a safe place.
Physical characteristics
As a rule, external hard drive is located outside the computer case, in its own case. This portable case is slightly larger than the external hard drive , and it sometimes contains a cooling fan. External hard drive connected to the computer via a special interface cable, which allows you to exchange data with external hard drive with a computer so that data can be transferred back and forth.
Why is it needed?
Access to the Internet regularly exposes computers to potential security threats such as Trojan horses, viruses and spyware. It has become increasingly difficult to protect against these threats, even with the use of firewalls and antivirus programs. Typically, several family members share a computer and the same system, entering confidential documents with a high risk of accidental damage or loss. In addition, the space required for multimedia files has skyrocketed; digital media files often take up large amounts of space on hard drive user. All these problems can be solved using external hard drive .
Advantages
Portable or external hard drive allows the user to be able to backup or storing important information separately from the main internal hard drive which could become compromised or corrupted. Confidential documents, large music files, movies, images and other files can be transferred securely and securely to external hard drive . Another advantage external hard drive is that it is portable and plug-and-play so that other compatible computers can recognize the drive as a storage device and can use it to access files. User can easily transfer files from computer to portable hard drive or external hard drive from your computer, or all programs can be launched directly from external hard drive .
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!
By tradition, let's look at the definition of a hard drive on Wikipedia:
Hard drive (screw, hard drive, hard magnetic disk drive, HDD, HDD, HMDD) - a random access storage device based on the principle of magnetic recording.
They are used in the vast majority of computers, and also 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 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 is an important difference between permanent computer memory and temporary memory ().
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 drive capacity to store data that does not fit in RAM (swap file) or storing the contents of RAM 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 — 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 inner part, where the heads are lowered (parked) during downtime, so as not to damage the working surface of the pancakes.
This is 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 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 the state of the hard disk and other necessary information about it, located on the so-called zero track, is read. 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.
This is basically how a computer hard drive works. In reality, everything is much more complicated, but the average user most likely does not need such details, so let’s finish this section and move on.
Types of hard drives and their manufacturers
Today, there are actually three main hard drive manufacturers on the market: Western Digital (WD), Toshiba, Seagate. They fully cover the demand for devices of all types and requirements. The remaining companies either went bankrupt, were absorbed by one of the main three, or were repurposed.
If we talk about the types of HDD, they can be divided as follows:
- 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 a PC - in this case it is also possible to use 2.5" hard drives, but as a rule, 3.5" are used;
- External hard drives are devices that are separately connected to a PC/laptop, most often serving as file storage.
There is also a special type of hard drive - 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 a HDD. This figure can reach 10 TB, although for a home PC they often choose 500 GB - 1 TB;
- Form factor — 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 in PCs and servers. The form factor also affects the volume, since a 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) 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 also such interfaces as SCSI, SAS;
- Buffer volume (cache memory) - a type of fast memory (like RAM) installed on the hard drive 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:
The need for formatting usually arises in two cases: when installing an operating system on a new hard drive and when cleaning the disk from old or virus-infected files. The initial formatting of a new hard drive is performed by the operating system itself when it is installed. If the user installs the OS on an already used disk, during installation he will have the opportunity to keep the existing formatting or select a new one. Operating Windows systems XP and Windows 7 use NTFS formatting. This means that when formatting, an order will be established for organizing, naming and storing files on the disk, corresponding to the principles NTFS systems. operating room Linux system uses ext2 and ext3 system formatting. Formatting is a necessary operation that prepares a hard drive or flash drive for recording information. How to format? If you have multiple hard drives or a disk with multiple partitions, you can format any disk and partition except the one on which the operating system is installed - it simply will not allow this. To format, open: “Start - My Computer”, select the disk you need and click on it right click mice. From the menu that appears, select Format. In the window that opens, select the type file system and formatting method. If “quick” formatting is selected, then only the file allocation tables are cleared, but the files themselves are not deleted. Something similar will happen if you tear out a page with a table of contents from a book - despite the absence of a table of contents, the text can still be read. Do not use quick format when installing the OS, especially if you install Windows XP after Windows 7. The remaining Windows files 7 may cause errors during the installation process. The same is true when cleaning a disk infected with viruses - if you cannot remove viruses in any other way, perform a full format. Sometimes there is a need to securely delete some information. Remember that even after complete formatting, you can restore the vast majority of information stored on the disk; for this, use special utilities recovery. Therefore, to guarantee the removal of information, special methods and programs are used that allow not only to delete information, but to write in its place several times and erase a random sequence of numbers. It is believed that for guaranteed deletion it is necessary to apply up to seven cycles of recording and erasing information. You can format a disk and ensure that information is erased using Acronis. Disk Director. There are two main versions of it: one runs under Windows, the second works with installation disk. Otherwise their capabilities are the same. With this program you can perform any operations with disks - split them, merge them, format them, assign drive letters.
