What is an SSD drive? What is an SSD drive and how does it differ from an HDD drive?
The abbreviation HDD - hard-disk drive - many have already memorized and understand that it is a hard drive. But what is SSD - a new abbreviation that has been used even more often than HDD in recent years? Read about this in our article.
SSD: decryption
SSD stands for solid-state drive and is translated into Russian as “solid-state drive” or, less accurately, “solid-state drive”. Behind this abbreviation lies a new data storage technology, more advanced than traditional ones. hard drives.
SSD drive: what is it?
So, what is it - an SSD drive? Main feature Such a drive has no moving parts. Conventional hard drives store data on rotating platters, and this rotation causes a number of disadvantages: firstly, it slows down the reading of data, secondly, it accelerates the wear of the drive and makes it more vulnerable to shock, and thirdly, it generates noise at work.
Nothing rotates in an SSD - the data here is stored in flash memory, and is written and erased using electric charges. Thanks to this, solid-state drives operate very quickly, do not produce any sounds, and are more resistant to shocks and falls.
True, this technology also has disadvantages. SSDs are significantly more expensive than hard drives of comparable capacity. In addition, the specifics of flash technology impose a limit on the number of rewrite cycles, so theoretically SSDs can fail earlier than hard drives, although practically modern solid-state drives are quite capable of successfully withstanding the average lifespan of a typical user computer.
What is an SSD for?
Since a solid-state drive, as mentioned above, is not the cheapest pleasure, you should not thoughtlessly buy it to replace a regular hard drive. For storing large amounts of data that do not require high read speed, SSD is still not best choice. You shouldn’t use it for files that are overwritten many times during the day, otherwise the drive’s service life will quickly come to an end.
It is best to install an operating system on the SSD - then it will work much faster. Both applications and games that require high speed reading data from the drive will benefit from this. Read our article on how to install a solid-state drive. And to store files, you should equip your computer with a second disk - a traditional HDD.
Advantages and disadvantages of solid state drives over HDDs... What are they?! Solid-state drives, or SSDs, having appeared on the market relatively recently, despite their high cost, have managed to gain popularity among users who value speed.
A solid state drive is a storage device that uses memory chips. The SSD also includes a management controller. The memory on which solid-state drives operate is divided into two types: flash and RAM.
Most often, SSDs are used in small devices (communicators, laptops, smartphones), where a significant requirement is the drive's resistance to shock and vibration, as well as its small size. The use of solid state drives in PCs provides a noticeable increase in performance.
The popularity of SSDs is growing very quickly: their cost, although currently noticeably higher than HDDs, is gradually decreasing; Some companies, which include, for example, the company that sold its hard drive manufacturing business to Seagate Samsung, have already completely abandoned the production of HDDs, switching to the development and creation of solid drives.
History of the origin and further development of SSD
Despite the fact that solid-state drives have become widespread only recently, the first prototype of such a storage medium was created back in 1978. The first semiconductor drive based on RAM memory was developed by StorageTek (USA). Four years later, another American company, Cray, began using SSD based on RAM memory in its Cray-1 and Cray X-MP supercomputers.
The first semiconductor flash memory drive was developed in 1995 by M-Systems (Israel).
Since 2005, laptops and netbooks containing SSDs have increasingly appeared on the market. The first company to release a device with solid state drive 4 GB in size, was ASUS. Gradually, the speed and volume of devices increased. In 2008, the developers of Mtron Storage Technology ( South Korea) presented at an exhibition in Seoul a 128-gigabyte solid-state drive with write and read parameters of 240 MB/s and 260 MB/s, respectively. In 2009, OCZ developed SSD capacity 1 terabyte.
Benefits of SSD
The advantages of solid-state drives are obvious. The absence of moving parts has led to their high mechanical resistance, fast reading of files, regardless of the location of their fragments, and absolutely silent operation. Read and write speeds are many times greater than the throughput of the best HDD interfaces, including SATA II, SATA III and others.
The absence of magnetic disks has made it possible to significantly reduce the size of the SSD, as well as reduce the influence of external electromagnetic fields on it, which can easily cause harm hard drives and the information stored on them.
SSDs are also characterized by a wider temperature range and low power consumption.
Disadvantages of modern SSDs
The key disadvantage of solid-state drives, due to which not many people can afford to install them in a PC, is their high cost, which is directly proportional to their capacity. The price of HDDs that are more common today depends solely on the platters they contain and increases much more slowly as their volume increases.
The main disadvantage of NAND SSDs (drives based on the use of non-volatile memory) is, first of all, a limited number of rewrite cycles: ten thousand for regular flash memory (MLC, Multi-level cell) and one hundred thousand for a more expensive type (SLC, Single-level cell). In order to prevent uneven wear, special circuits are built into the SSD: the controller stores information about which blocks are the least rewritable and, if necessary, begins to use them more actively. Number of cycles for RAM SSD and latest technology FRAM is almost limitless, enough for 40 years of continuous use.
Inability to recover information
Solid state drives do not allow data recovery due to the use of the TRIM command, so all recovery utilities become useless. In addition, information on the SSD becomes irretrievably lost if the voltage is exceeded or dropped. If in hard drives Most often, only the controller board burns out, the solid-state media burns out completely. A hardware failure of an SSD that occurs due to a failure of the controller chip or flash memory will result in information being lost without the possibility of recovery.
SSD and choice of Windows operating system
The acceleration of SSD wear is also affected by the use of outdated and even a number of current operating systems that do not take into account their specifics. The reduced service life of solid-state drives due to the operation of some OS services is due to the fact that they are designed only to work with HDDs,
Therefore they are used on SSD technology, which speed up work hard disks, but do not have any positive effect on the performance of solid-state drives, but on the contrary, reduce their service life.
In the OS family Windows optimization working with SSDs was introduced only starting from the seventh version. On hard Windows drives 7 does not use defragmentation, as well as Superfetch and ReadyBoost technologies needed to speed up reading and writing on hard drives. Previous Windows versions, including the relatively recent Vista OS, require additional settings to reduce SSD wear. First of all, you need to disable defragmentation, which still does not have any effect on the performance of solid-state drives.
Setting up Windows 7 to work with SSD
In order to prevent rapid wear of the SSD, you should disable some services and operations on the system.
First of all, you should disable the use of the paging file in the system, which is designed to store temporary data, which is necessary when there is insufficient RAM. However, writing and rewriting to an SSD so frequently will cause the memory cells to wear out quickly. Therefore, if your memory exceeds 4 GB, the best solution will disable the page file. If the memory size is less than 4 GB, then the easiest way would be to move the page file to the hard drive or increase the amount of RAM.
Indexing and SSD caching is absolutely unnecessary operations, since the solid-state drive already works very quickly.
Due to the fact that direct SSD access to files is very fast, defragmentation is unnecessary, moreover, it only harms the SSD cells.
Another operating system component that became unnecessary after installing it on an SSD is Prefetch and SuperPrefetch, designed to speed up the initial boot and launch of programs.
To disable these services, open Windows registry and change the EnablePrefetcher and EnableSuperfetch values to zero.
SSD and alternative operating systems
TRIM support for solid-state memory was introduced in Mac OS X version 10.7 (Lion). In 2010 Apple company launched Air computers, which included solid-state memory. Initially, at the buyer's request, the SSD could be replaced with regular hard drive, however, starting in 2010, the company completely abandoned the use of HDDs in this line to reduce the size of the computer case, as well as reduce its weight. The memory capacity in the Air line ranges from 64 GB to 512 GB.
In 2012, it went on sale new MacBook Pro, powered by flash memory. Optionally, you can install up to 768 GB of flash memory into your computer.
TRIM support for SSDs in operating rooms Linux systems appeared starting with kernel version 2.6.33. In the drive mounting settings, you should specify the “discard” option.
SSD or HDD: what to choose?
Currently, solid-state drives are increasingly winning back hard drives market share. And although it is still too early to talk about the onset of the final transition to SSDs and removal of HDDs from sale, it is becoming clear that at some point this will become inevitable. Those who have installed a solid state drive as system disk, we have already seen the difference in performance, which is noticeable even without the use of special tests.
Flash memory drives feature fast access times, high data transfer rates and improved performance, allowing you to work with the operating system and installed applications much faster. In addition, the SSD is characterized by absolutely silent operation, reliability and low power consumption.
At the moment, there are many solid-state drives from various manufacturers on the component market, so choose the best one among them. best option not so simple. However, the speed of any SSD model, even the slowest and cheapest, is many times higher than the same one. hard parameter disk.
Let's compare each of technical parameters SSDs and HDDs separately.
Performance
Almost every SSD is two or three times faster than a traditional hard drive in terms of interoperability. Launching programs and the operating system, resuming from sleep or standby mode, installing applications, working with files (copying, archiving, unzipping) is noticeably faster on solid-state drives.
To determine the higher performance of an SSD, you don’t even need to do any measurements, since it is easy to notice even by eye. Launch software becomes much faster, the operating system also runs without delay. Particularly noticeable is the speed of entering and exiting standby or sleep mode.
SSDs are an excellent choice for users who value speed.
Comparison of HDD and SDD performance
If you test for comparison purposes one of the currently best HDDs Seagate Barracuda XT with a capacity of 3 TB and a speed of 7200 rpm and Samsung SSD 470 Series from the previous generation, it becomes clear how noticeably different the performance of HDDs and SSDs is.
Futuremark PCMark 7, simulating standard computer operation, demonstrates that in almost any type of work the SSD performs the task three to four times faster than hard disk. At the same time, this test takes into account system performance, taking into account the influence of the CPU and video card, which allows you to see a picture almost similar to that created during normal use.
The only exceptions, when the results of HDD and SDD are almost equal, include working with video in Windows Movie Maker and loading Windows Media Center.
The most striking example when a user can see and evaluate the speed of a storage medium is when transferring and copying data. On older computers, this time can take such a long period that the user is forced to sit in front of the screen and wait for file operations to be completed.
A comparison of three media: SSD, 7200 RPM HDD and 5400 RPM HDD shows how much faster SSDs are. During this testing, files were copied and transferred from one logical drive to another, which resulted in the media simultaneously reading and writing data.
As we see, SSD speed when working with files and archives, it is several times greater than the capabilities of the hard drive.
This test allows you to determine how noticeable the performance of the SSD will be when solving daily tasks that the user constantly faces. Two types of programs were selected for testing: 1) those that are most often used by users, 2) large packages, the installation of which usually takes a very long time.
Testing has shown that the speed of installing applications on an SSD is two or three times faster than on an HDD. The only exceptions are Acronis programs and Office 2007.
The advantage of the SSD also remains when launching applications, although in this case the time period is so short that it is unlikely to be very noticeable to the user.
File capacity and storage capacity
If you need storage media for large amounts of information, such as videos or movies, then it would be much better to opt for a hard drive. Purchasing an SSD to store files on it is an unnecessary luxury, since the cost of solid-state drives is noticeably higher and, moreover, directly depends on its volume. Even the smallest 128 GB model is very expensive, while a 500 GB hard drive can be purchased at a very low price.
However, if you plan to use an SSD as a system one, then the current minimum volume of 128 GB will be enough for you. This volume is quite enough to create working system, where Windows 7 will be installed, necessary programs and even a few games. And to store multimedia files and archives, you can install an additional HDD. If you are going to install an SSD in your laptop, then you can purchase an external hard drive to store files.
Reliability and resistance to shock and vibration
A significant parameter of an SSD that distinguishes it from hard drives is its reliability in use, which is ensured due to the fact that the solid-state drive is absolutely insensitive to shock and vibration. This is especially true for laptops, which you often have to carry with you. Such devices are often subject to shock, and sometimes only the built-in accelerometer, which turns off the HDD when dropped, saves it from data loss or damage.
Using an SDD allows you to forget about trying not to shake your laptop. For example, when the device barely begins to go into sleep mode (and at this time it is very actively writing data to the media), you can already put it in your bag. If you do this with a laptop with a built-in HDD, the hard drive will easily be damaged.
Durability of SSD and HDD
At the same time, SDDs are still inferior to hard drives in terms of their durability. Inexpensive first-generation SSDs installed, for example, on EEE PCs, have already begun to gradually fail. And if it is almost impossible to predict the mechanical wear of HDDs, then solid-state drives have a limited number of rewrite cycles, which is currently its main disadvantage.
It is expected that the development of technology will lead to the fact that non-volatile memory will be made from other materials, such as, for example, FeRam, but such drives are not yet commercially available. In 2014, HP plans to begin selling drives based on ReRAM technology.
Physical dimensions of both media
For some users, a significant advantage of SSDs is their light weight and size. Solid-state drives are noticeably smaller than hard drives, which, firstly, makes it possible to significantly reduce the size of the device (this is especially true for laptops and netbooks), and secondly, it allows you to place a larger number of drives in a PC case rack.
Cost of SDD and HDD in comparison
Price is the parameter by which SSDs are hopelessly inferior to hard drives. Modern solid-state drives cost three to four times more than an HDD, which has three times the capacity.
It's up to you to decide whether it's worth spending money on performance and speed. In our opinion, this only makes sense if your work with a PC or laptop is constant and active. In this case, you will save not only time, but also your nerves, getting rid of the irritation associated with the fact that the system and applications are very slow.
What should you choose?
Although SSD technologies are developing very actively, there is no talk of a time when they will completely replace hard drives, it's still early. Solid-state drives have no equal in providing higher performance and speed when used as system drives, but they are noticeably inferior to HDDs when it comes to storing files.
For most of the tasks faced by home PC users, a configuration with two media is perfect: an SSD, where the operating system should be placed, and executable files and program caches, and large HDDs for storing movies, music, photos and documents.
A budget option can do just fine without the use of solid-state drives, but computers that work exclusively with SSDs, due to their unreasonably high cost, are extremely rare.
Probably every person who is familiar with computer technology knows or has at least heard of such a device as an SSD drive. What is it and what role does it play in the operation of a computer? In short, SSD is used to record and store the user's personal data. You could argue that that's what hard drives are for. And this statement will be absolutely correct, because these components of the computer perform identical functions. So why was the SSD invented, what is it, how does it work and how does it differ from a regular HDD? All these questions can be answered in this article.
What is the difference between a hard drive and an SSD hard drive? What kind of device is this and what are the main principles of its operation?
Today, the main place to store most files on a computer is the hard drive. If you take it apart, you will find a rather fragile mechanism inside. It consists of magnetic plates rotating on a special head. A carriage moves between these plates, which finds and reads the necessary information. The hard drive mechanism resembles a gramophone, but these devices perform different functions. Unlike the mechanism of a musical device, the hard drive carriage moves at a speed of several thousand revolutions per minute and performs work related to copying and recording information.
As for the SSD disk, or, as it is commonly called, a solid state drive, it is used for the same purposes as a hard disk. It just works completely differently. There are no moving elements inside this device, but special chips are installed to store information. A solid-state drive resembles a large flash drive that can be placed in place of a hard drive.
Basic principles of operation of solid-state drives
The memory of SSD disks consists of special blocks that are divided into cells where the necessary data is stored. Everything would be fine, but the main problem arises when you need to delete or re-record existing information. The fact is that it is impossible to delete part of the information from one block, but you have to format the entire sector. In this case, the necessary data is stored in the cells of neighboring blocks and only then overwritten in the old place. Suppose you need to save data of 10 KB in size. In this case, the memory block has a volume of 20 KB, 10 KB of which are already occupied. In this case, the information available on the disk is transferred to another location, the entire block is deleted, and only then the old and new data are written. It turns out that to carry out one operation, the system performs several additional actions, which leads to slower operation and accelerates the wear of the solid-state drive.
To increase device performance, you must use special program TRIM, or SSD trimming as it is sometimes called. What it is and how it works, we will consider further. TRIM is not even an application, but a special command that the operating system sends to the SSD to indicate unused elements. Thanks to this function, you can immediately delete unnecessary files, avoiding additional operations with transferring information to neighboring blocks. And this significantly improves SSD performance. But this command is not supported by older versions of operating systems. Therefore, to connect TRIM, Windows 7 or 8 must be installed on your computer, Linux versions 2.66.33 or higher.
What does an SSD consist of?
Having studied the differences between the two types of information storage, we will dwell in more detail on how SSD solid-state drives are designed, what kind of devices they are and how they function. In appearance, this is an ordinary box with connectors for connecting to a computer. Mainly SSD drives for home use are equipped with Sata, USB 3.0 and PCI-Express interfaces, which easily provide the required writing and reading speeds.
SSDs do not have any moving mechanical parts. Thanks to this, they are much more resistant to external factors. For example, an ordinary HDD disk is a rather fragile thing, because if during shaking or falling the read head comes into contact with the magnetic plate, this will lead to the failure of the media. But solid-state drives are designed completely differently. Inside these devices, special boards are installed on which memory chips and a controller are soldered. Some SSD drives are additionally equipped with compact batteries, which, in case of sudden shutdown electricity provides the cache with additional power, and the data is stored on the main memory chips. Now let's take a closer look at the main components of a solid-state drive.
SSD memory: what is it and what are its main functions?
Most SSD drives use NAND, or, as it is also called, flash memory. Similar chips are used in regular flash drives, only in solid-state drives they are more reliable and have greater speed due to the presence of a controller. Due to their low cost, they are widely used in SSDs, making these devices quite affordable for most users. Another advantage of this is that it is non-volatile and will not require additional food for work.
In addition to NAND technology, solid-state drives sometimes use RAM-SSD. This type of memory has a high speed of writing and reading data due to the use of chips used to create RAM. It will require a constant connection to electricity, so SSD drives that use RAM often have additional batteries installed in case of a sudden power outage. Due to the high cost of producing these drives, they are rarely found in home PCs and laptops. RAM-SSDs are mainly used in computer systems of large companies to increase the speed of working with databases.
Today, most drives use NAND memory. Despite this, these SSD drives differ from each other in speed of writing, reading data and cost. It all depends on the chips used in the drive: SLC, TLC or SSD MLC. What is it and what is the difference between them? This is how different ones are designated. The most common technology is MLC, thanks to which two bits of information can be stored in one cell. TLC makes it possible to write as many as 3 bits, but this leads to faster cell wear, so this technology is not very popular. The fastest and most durable is SLC memory, with which you can write only one bit of data in each cell. Among the disadvantages, one can highlight only the high cost, which is 2 times higher than SSD price MLC.
Controller
The controller is the most important element, without which the SSD cannot function. What it is and what its role is, we will find out further. These devices perform the work of distributing the load between memory blocks, are responsible for reading and writing information, error correction and file compression. The controller resembles a command center where decisions related to data processing are made. The speed of operation of the solid-state drive and its durability depend on this detail. The main component of the controllers is a special microprocessor, which bears the entire load. Also, the performance of the device depends on the quality of the firmware.
Quite a lot of companies are engaged in the production of SSD drives, because the technology for their production is quite simple and requires less time than creating a classic hard drive. All you need is to purchase memory chips, controllers and boards where everything will be soldered. After this, the structure is placed in beautiful body with a company logo - and the product is ready for sale. But the components themselves for solid-state drives have a high price, and the creation of a controller and high-quality firmware for it will require large expenses. Because of this, the cost of SSD drives today is much higher than conventional HDDs.
Hybrid SSD HDD
Now let's look at the hybrid SSD HDD. What is this device and what is it intended for? Every year, solid state drives are gaining more and more popularity. Technology does not stand still, and standard hard drives are gradually replacing more technologically advanced systems. SDD drives are present in many computers, but are used not as the main storage of information, but as an additional one. And all because their cost is significantly higher compared to conventional hard drives. To compensate for this gap between the two types of drives, it was created hybrid HDD SSD. Let’s try to consider in more detail what kind of device this is and what advantages it has.
The hybrid drive is based on the same HDD without any changes. But chips with flash memory are also installed in the body of these drives, which are used as a buffer zone. The information that is most frequently used is copied to it. This made it possible to increase the loading speed of some applications and the operating system itself when compared with conventional hard drives. The maximum amount of flash memory in such hybrid SSDs is 8GB. What was the result? In fact, we have something between a hard drive and a small solid-state drive. You cannot load data or install applications into buffer memory. It is used as a reserve for running priority programs that the user cannot control independently. As for the price, the cost of hybrid drives is lower than standard SSDs, but higher than HDDs; moreover, they are not very popular in our country, so they are not sold everywhere.
Benefits of a Solid State Drive
An integral part modern computer is an SSD drive. We have found out what kind of device this is and how it works, all that remains is to highlight its main pros and cons compared to conventional HDDs. Let's start with the positive aspects of SSDs.
The most important advantage of an SSD is its incredible storage of information. They are several times more productive than hard drives. For example, the data processing speed of some drives exceeds 500 MB/s. In practice, this results in faster operation of programs and the operating system itself, which loads in a matter of seconds. This is very important, because the current generation of computers has high performance, which is greatly slowed down by HDDs. But with the advent of new drives, their speed has increased significantly.
Another advantage of SSD devices is their higher resistance to external factors. They do not have such a fragile mechanism as hard drives. Thanks to this, they can easily withstand shaking, vibration and moderate impacts to the body. These devices will be an excellent solution for laptops. In addition, they cope better with temperature changes.
Another advantage of SSD is its quietness and low power consumption. Because hard drives have moving mechanical parts, they produce a certain level of noise. In addition, in working condition, HDDs have enough high temperature, so the coolers have to spin at an accelerated rate. But all these problems are absent from SSDs, which do not heat up, do not make noise and consume less electricity.
Flaws
Having assessed all the advantages of solid-state drives, it remains to find out what weaknesses the SSD hard drive has. What are these flaws? The first of them is the high cost of such drives. Despite the simplicity of their design, manufacturing flash memory chips and controllers is quite an expensive business. But there is no need to be upset about this, because technology is constantly developing, and the price of these goods is gradually decreasing. In a couple of years, they may well be equal in price to HDDs.
After the first drawback, a second one can be identified. Due to their high cost, SSDs have less storage capacity than HDDs. For example, the memory capacity of some HDDs is 8 TB, while SDDs only reach 1 TB.
SSD memory is short-lived and will fail after a certain number of write cycles. Although the current generation of these devices has a fairly long service life, you must be prepared for the fact that one day the drive will stop working, and it will be problematic to restore information.
I would like to add that SSDs do not tolerate power surges quite well. If after one of these voltage drops it burns out, then it will be impossible to obtain data. In the case of an HDD disk, a certain sector in it will fail, but most of it will remain intact, thanks to which all undamaged information can be retrieved.
What should you pay attention to when buying an SSD?
Having studied the information about solid-state drives, many users probably wanted to purchase this device for their computer. But you don’t have to immediately run to the store and grab the first product that comes your way. Here are some tips to help you choose an SSD.
First you need to pay attention to the size of the SSD. What is it? In other words, this is the amount of built-in. The higher its value, the more information can be recorded. But you don't need to buy the most expensive goods, because solid-state drives are mainly used for installing operating systems and applications on them, and the main place for storing data is still the hard drive. Having completed your SSD system with just 60-120 GB, you can achieve a significant increase in the speed of your computer.
Reading and copying speed plays an important role. The higher it is, the better, but it happens that the motherboard cannot reveal the full potential of the SSD drive due to the low bus bandwidth. It happens that there is no point in installing fast drives in old laptops or PCs at all, because even after the update the system will work the same as on a regular HDD. Therefore, it is worth studying the configuration of your computer, and only then going to the store. The largest ones are, and for outdated IDE ports you will need a special adapter to install an SSD.
The most important component of any SSD is the controller. It is this detail that controls all processes associated with information processing. The durability of the entire device depends on how well it is made, so it is recommended to give preference to proven and proven manufacturers. The leaders in production are SandForce, Marvell, Intel, Indilinx.
Finally, you should pay attention to the dimensions of the drive. For a PC this is not so important, because in system unit You can install any SSD, but problems may arise with laptops.
Basic rules for using solid-state drives
After looking at reviews from users and experts, we can conclude that an SSD hard drive is an integral part of a modern computer. We have already looked at what it is and how it works. Now you need to learn how to use it correctly. As strange as it may sound, in order to understand all the advantages of solid-state drives, you need to follow a few simple rules.
There is no need to fill all available memory to capacity. Many people neglect this rule, because SSDs are quite expensive, so users buy small drives and completely load them with necessary and not so necessary information. But we must remember that if you leave less than 25% free space, then the data processing speed will decrease significantly. The fact is that the more memory, the higher the number of free blocks where data can be written. When there is too little space left, information is distributed across the cells of neighboring blocks, and this leads to a decrease in performance.
It is worth remembering that using solid-state drives you can significantly increase the performance of your computer, so it is recommended to install the operating system, applications and demanding games on them. But you should use HDD as the main storage of information. This will be more economical and practical, because they can easily cope with playing audio and video files no worse than SSDs.
It is best to have one of the latest versions of operating systems installed on your computer. For example, Windows XP or Vista are poorly optimized for working with solid-state drives and do not support the TRIM command.
We tried to figure out what an SSD drive is and how it differs from classic hard drives. Concluding the general description, today we will focus on the form factor of the drives. SSD Dimensions cannot be arbitrary, but are subject to certain standards. Let's see what they are.
What is form factor
This is a certain set of requirements that must be met in the production of this or that computer component. Power supplies, motherboards, disks, cases designed to install motherboards of one or another form factor, etc. have a form factor.
This ensures that when installing a disk, motherboard or power supply into the case, all mounting holes, the location of interface connectors (for drives) will be the same for all devices, regardless of manufacturer, model, functionality. So, motherboards mATX form factors of any brand have the same overall dimensions and the location of the holes for screwing to the body.
The same goes for disks. 2.5-inch drives, no matter hard drives or SSDs, have the same external dimensions, location of contacts and holes for fastening. The whole difference lies inside, in the filling.
There are several drive form factors in use today, with SSDs offering a wider variety of sizes. This is due to the absence of moving parts and the theoretical possibility of making any shape. Naturally, to be able practical application, this “form” must be standardized.
2.5 inch drives
The now familiar size of small laptop drives rivals traditional 3.5-inch drives. Most likely, there is no talk of active displacement of larger disks by compact analogues, but for SSD optimal It turned out to be exactly the size 2.5 inches.
Externally, an SDD differs from a HDD only in its weight (SSD is much lighter) and the absence of any visible printed circuit boards. This is a fairly simple, if not boring, box. The connection is made to the SATA interface. Considering the speed characteristics of solid-state drives, connecting to SATA below version 3 does not seem reasonable. IN in this case, SSD will not reach its potential.
It must be said that here, in fact, the analogy with conventional hard drives ends. All other variations are the prerogative of SSD drives.
mSATA drives
A variation of regular SATA, characterized by compact dimensions, which is why the SSD itself lost its housing and became very small. This made it possible to use such capacious boards in compact computers, as well as install them in laptops, in addition to the usual hard drive, another drive, in this case an SSD.
In particular, on the laptop on which I am now writing these lines, in addition to a regular hard drive, there is an SSD drive in the mSATA format, which I use as a system drive. Even considering that I have a budget-class disk, the speed of operation, system loading, and programs has increased significantly.
This form factor, for the mSATA connector, did not last long, giving way to a more promising option.
M.2 drives
Perhaps the most interesting option for SSD drives. The advantages are compactness, the ability to work not only on the SATA bus, but also on the significantly faster PCI-Express. This connector can now be increasingly found in laptops and motherboards for desktop computers.
If when assembling a regular PC the issue of saving space is not so relevant, then in the case of laptop computer The ability to use a small, lightweight, energy efficient, and fast drive is a boon.
When choosing M.2 drives, there is a little confusion, which is based on the fact that the drive can operate on different buses, i.e. use SATA or PCI-Express. Therefore, the drives have a different key, i.e. a cutout on the contact connector.
As a rule, SSD drives come with keys:
- B-key. SSD drives for SATA or PCI-Express x2 interfaces. In reality, this option is extremely rare.
- M-key. SSD drives for PCI-Express interface x You can use drives with an emulated SATA interface. A drive with such a key cannot be installed in a slot with a B-key operating on the SATA bus.
- M&B (M+B) key. A universal option for SSD drives running on the SATA bus. Can be installed in both B-key and M-key slots.
The form factor for SSD M.2 is also regulated in terms of length and width. Typical sizes of SSD drives are 22 mm wide and long, ranging in size from 16 to 110 mm. Full list of acceptable length dimensions: 16, 26, 30, 38, 42, 60, 80, 110 mm. The most common are 42, 60 and 80 mm.
This is reflected in the labeling of SSD drives. So, if it is indicated that the M.2 drive is 2242, then this means that the dimensions of the drive are 22x42 mm. If M.2 is 2280, then, accordingly, 22x80 mm. It's simple!
Even if the motherboard does not have an M.2 connector installed, you can still use such drives. Many manufacturers offer drive models with an adapter card for a PCI-Express connector. Accordingly, the SSD itself is also designed to work with this bus. The “rate of fire” of such a disk will be very impressive. After it, the performance of a regular hard drive will be perceived as depressing.
Unfortunately, there is a small fly in the ointment in all of the “goodies” listed. The compact size of SSD drives limits storage capacity. This is due to the number of memory chips that can be placed on such a small board. The maximum capacity of an M.2 SSD drive currently does not exceed 1 TB. This value will be increased by more capacious memory chips, which will undoubtedly appear.
PCIe Add-in Card (AIC)
These are drives made in the form of a board inserted into a PCI-Express slot, which can be standard or half size in both length and width, which allows them to be used in 2U rackmount enclosures. Actually, such SSDs belong to the corporate class and are intended primarily for installation in servers and storage systems (Data Storage Systems).
As a rule, drives use SLC memory, which is expensive in itself, but reliable and durable. Use such disks in normal home computer- a luxury that is not available to everyone. True, there is no particular need for this.
SATA-Express drives
Finding such discs is almost impossible. This interface was planned to replace the good old SATA with its leisurely 600 MB/s maximum throughput. It was too tempting to use the faster PCI-Express bus. So this interface was planned to use 2 PCI-Express lines, which would allow achieving a maximum throughput of 2 GB/s.
Apparently, this interface will remain one of the stages that has not found implementation, since already now M.2 SSD drives can use 4 PCI-Express lanes with a peak throughput of 4 GB/s. A special cable is used for connection.
U.2 drives
There are also such SSD drives. This form factor allows you to use all the advantages of the high-speed PCI-Express bus, but not be limited to drives with an M.2 connector. Externally they resemble 2.5-inch drives, but with a thickness of up to 15 mm. 4 PCI-Express lanes are used.
The choice of such drives is very small, and they are mainly aimed at use in servers, storage systems (data storage systems), data centers, etc. If the motherboard has an M.2 connector on the PCI-Express bus, and there is SSD drive of U.2 form factor, then you will still be able to connect it. There are M.2 to U.2 adapters, which will allow you to experience the full power of such a high-speed drive.
At the moment, this form factor is rather a thing of the future, and primarily it is relevant for servers.
DIMM drives
If we talk about the exotic, there are also sizes of SSD drives that are completely identical, coincide with the sizes of conventional memory modules, and are installed in a free RAM slot. This may be relevant for specific server platforms with a large number of DIMM slots.
There are different options, combined on one SSD and RAM module, or only a solid-state drive inserted into the connector for RAM, receiving power from it, but data is transmitted using a regular SATA cable connected to the module and the motherboard or controller.
This is of little interest for home computers, and it’s difficult to find them on sale.
SSD sizes. Conclusion
So, to briefly summarize, the size of SSD drives, i.e. the form factor, determines the physical dimensions of the drive, which also affects its characteristics. A 2.5-inch laptop hard drive can be easily replaced with the same SSD. It will fit both the location of the mounting holes and connectors - power supply and interface.
If your computer has an M.2 connector that supports, for example, 2242, 2260 and 2280 drives, then you can also install a suitable SSD. The main thing is not to make a mistake about which bus this interface uses and, accordingly, which key is in the connector. An SATA bus SSD with an M+B universal key can be used in any computer with an M.2 connector. If the SSD uses the PCI-Express bus, then it has an M-key, and can only be used in an M.2 slot running on this bus (also with an M key).
These are the 2 most common form factors of SSD drives at the moment. The choice in favor of one option or another is determined by layout considerations, necessity, cost and a number of other reasons.
This is where we’ll finish talking about the sizes of SSD drives, and in the next article we’ll get into the insides. We will look at the ones that are used in these drives, what they are like, how they differ, what are the advantages and disadvantages.
Hello friends! Technologies do not stand still and are developing more and more rapidly every year, especially in the computer industry. It seems like just yesterday that we only learned about the three laws of robotics, written by Isaac Asimov, and today the Japanese are already designing dolls whose electronic “filling” is half as powerful as a small server room, but which have never even heard of the mentioned laws.
The changes also affected the area of data storage. Today you will find out what an SSD drive is and why it is needed, whether such a device is needed in principle or how you can do without it.
Why solid state
Such drives have been known for many years, but most users have only recently turned their attention to them as a worthy alternative to traditional hard drives. So why is it called solid state? The name comes from the English word Solid - “Solid state”. In fact, this is an ordinary microcircuit built on semiconductors - a green board with a bunch of tracks that everyone who has ever disassembled the body of an electrical device has seen.
The architecture of the device resembles the already familiar flash drives. SSD uses the same type energy saving schemes memory that does not lose data, even during a long power failure. The only difference is in dimensions, capacity and recording speed. In addition, the flash drive is designed to be used as a plug-in external device, and the SSD is still, in most cases, an internal device.
Externally, solid-state drives resemble hard drives, but differ in size - they are smaller. According to standardization, there are slightly different form factors: for example, M2 or U2. This does not mean that an SSD cannot be installed in a regular system unit: there are special adapters for old cases, and new cases are already equipped with mounting slots.
Benefits of SSD
A logical question may arise: why such a device in a computer at all, if there are familiar and affordable hard drives. And solid-state drives have several advantages: 
Higher data read and write speed. This is especially appreciated by users who process large files, as well as gamers whose games load faster.
Less power consumption. For laptop computers, this is a decisive factor, because the device can work longer on the same battery charge.
Longer service life. Due to the lack of mechanical parts, there is a higher chance that the device will not fail at the most inopportune moment.
Impact resistance. When transporting the device, there is a higher chance that the user will lose important data due to a fall or mechanical impact. This is the reason for the growing popularity of portable SSDs.
Often a small SSD is installed on a computer as a system volume to load the operating system faster. Such a computer will not only boot faster, but the OS will also be faster due to quick access to everyone system files.
Disadvantages and Limitations
You may ask: if this device is so gorgeous, why don't all users use it on PC? Alas, everything still comes down to cost: for the same price you can buy regular hard drive capacity ten times greater than SSD. When assembling or upgrading a computer, users are often limited in funds, so they have to “rein on their horses,” maneuvering between the coolness of the part and its cost. And so we would instruct everyone, yeah.
There is still a misconception among users that SSDs are unreliable. Yes, this was observed at the time of their mass appearance on the market. The reason lies in the use of cheap controllers that did not cope with their task. Today, the cheapest SSD is guaranteed to “survive” up to 3,000 rewrite cycles. For higher quality devices, this figure increases to 10,000. This is even more than a traditional HDD. 
Another myth is that the operating system must be somehow cleverly configured to work with a solid-state drive - for example, disabling the page file. This is wrong. All the user has to do is activate the AHCI mode in the BIOS, which is necessary for correct operation devices. Please note that older motherboards do not support this mode - instead there is a now obsolete IDE
Why is it needed?
“To be or not to be?” - the reader will think. Buy an SSD or save money by buying something else. According to reviews from my clients, no one has ever experienced dissatisfaction with the purchase of such a device. There have been several complaints about warranty repair, but this is already a statistical error, which always manifests itself when large quantities sales
And if you get nervous every time your computer starts to slow down and freeze, an SSD is the best option to get rid of such phenomena. You will most likely not stop being nervous, but you will already find another reason, but the computer will “fly” with such a drive.
True, there is one small “BUT”. You quickly get used to good things, and then work on a computer with regular HDD you will feel a little uncomfortable. But these are little things, aren’t they?
And if you are already heading to an online store for a brand new SSD drive, read these instructions - it will help you correctly. You might also be interested, of course, if you think that you can’t live without an HDD.
I advise you to pay attention to the Kingston SSDNow A400 120GB 2.5″ SATAIII TLC device - a good and affordable 120 Gb drive.
And with that, I say goodbye for today. Thank you for your attention, friends, and see you next time. Don't forget to share my blog posts on social networks. Computer literacy- to the masses! And to receive notifications about new articles.