Probably every person who is familiar with computer technology knows or at least heard about a device such as an SSD drive. What is it and what role does it play in computer operation? In short, an SSD is used to record and store personal user data. It can be argued that there are hard drives for this. And this statement will be completely correct, because these components of the computer perform identical functions. So why did they invent an SSD, what is it, how does it work, and how is it different from a regular HDD? You can find answers to all these questions in this article.
What is the difference between a hard drive and an SSD hard drive? What is this device 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 disassemble it, then inside you can find a rather fragile mechanism. It consists of magnetic plates rotating on a special head. Between these plates moves the carriage, which finds and reads the necessary information. The mechanism of a hard disk resembles a gramophone, only these devices perform different functions. In contrast to the mechanism of the musical apparatus, the Winchester carriage moves at a speed of several thousand revolutions per minute and performs the work associated with copying and recording information.
As for the SSD-drive, or, as it is commonly called, a solid-state drive, it is used for the same purposes as a hard drive. It just works in a completely different way. There are no moving elements inside this device, but special chips are installed to store information. SSD resembles a large flash drive, which can be put in place of the hard drive.
Solid State Drives Fundamentals
The memory of SSDs 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 existing information or re-record it. The fact is that it is impossible to delete part of the information from one block, but it is necessary to format the entire sector. In this case, the necessary data is stored in the cells of neighboring blocks and only then are overwritten to the old place. Suppose you want to save data of 10 KB. In this case, the memory block has a volume of 20 KB, 10 KB of which are already taken. In this case, the information available on the disk is transferred to another place, the entire block is deleted, and only then old and new data is recorded. It turns out that for one operation, the system performs several additional steps, which slows down the operation and speeds up the wear of the solid-state drive.
To increase the performance of the device, it is necessary to use a special program TRIM, or, as it is sometimes called, truncation of the SSD. What is it 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 items. Thanks to this function, you can immediately delete unnecessary files, avoiding additional operations with transferring information to neighboring blocks. And this greatly improves the performance of SSDs. But this command is not supported by outdated versions of operating systems. Therefore, to connect TRIM, Windows 7 or 8, Linux version 2.66.33 or higher must be installed on the computer.
What does an SSD consist of?
Having studied the differences between the two types of information storages, we will dwell in more detail on how SSDs are arranged, what devices are and how they function. It looks like a regular box with connectors for connecting to a computer. Basically, SSDs for home use are equipped with Sata, USB 3.0 and PCI-Express interfaces, which without any problems provide the necessary write and read speeds.
Solid state drives do not have any moving mechanical parts. Due to this, they are much more resistant to external factors of influence. For example, a regular HDD-drive 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 damage to the media. But solid state drives are completely different. Inside these devices, special boards are installed on which the memory chips and the controller are soldered. Some SSDs are additionally equipped with compact batteries, which, in the event of a sudden outage, provide the cache with additional power, and the data is stored on the main memory chips. Now we will dwell in more detail on the main components of a solid-state drive.
SSD memory: what is it and what are its main functions?
Most SSDs use NAND, or, as it is also called, flash memory. Such chips are used in conventional flash drives, only in solid state drives they are more reliable and have a high speed of information processing due to the presence of a controller. Due to their low cost, they are widely used in SSDs, so these devices have become quite accessible to most users. Another advantage of this type of memory is that it is non-volatile and will not require additional power to work.
In addition to NAND technology, solid state drives sometimes use RAM-SSDs. 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 SSDs using RAM often install additional batteries 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. Mainly RAM-SSDs are used in computer systems of large companies to increase the speed of working with databases.
Today, most drives use NAND memory. Despite this, these SSDs differ in write speed, data reading 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 refers to different types of flash memory. The most common technology is MLC, thanks to which two bits of information can be stored in one cell. TLC makes it possible to record 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 the SLC-memory, with which you can write only one bit of data in each cell. Among the shortcomings, one can single out only the high cost, which is 2 times higher than the price of SSD MLC.
Controller
The controller is the most important element without which an SSD drive cannot function. What is it and what is its role, we will find out further. These devices perform work on the distribution of load between memory blocks, are responsible for reading and writing information, error correction and file compression. The controller resembles a command center where decisions are made related to data processing. The speed of operation of a solid-state drive and its durability depend on this particular part. The main component of the controllers is a special microprocessor, which carries the entire load. Also, the speed of the device depends on the quality of the firmware.
Quite a few companies are engaged in the production of SSD-drives, because the technology for their manufacture is quite simple and requires less time than creating a classic hard drive. All that is needed is to purchase memory chips, controllers and boards, where everything will be soldered. After that, the design is placed in a beautiful case with a company logo - and the goods are ready for sale. But the components themselves for solid-state drives have a high price, in addition, the creation of a controller and high-quality firmware for it will require large costs. Because of this, the cost of SSDs today is much higher than conventional HDDs.
Hybrid SSD HDD
Now let's look at a hybrid SSD HDD. What is this device and what is it for? Solid state drives are gaining more and more popularity every year. Technology does not stand still, and standard hard drives are gradually replacing more technological systems. SDD disks are present in many computers, but they are not used as the main storage of information, but additional. And all because their cost is much higher compared to conventional hard drives. To compensate for this gap between the two types of drives, a hybrid HDD SSD was created. What kind of device is it and what are its advantages, let's try to consider in more detail.
At the heart of the hybrid drive is the same HDD without any changes. But in the case of these drives are still installed chips with flash memory, which is used as a buffer zone. The information that is most often used is copied to it. This made it possible to increase the download speed of some applications and the operating system itself, when compared with conventional hard drives. The maximum flash memory capacity in these hybrid SSDs is 8GB. What is the result? In fact, we have something in between a hard drive and a small solid-state drive. You cannot load data or install applications into the buffer memory. It is used as a reserve for launching priority programs that the user cannot independently control. 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, therefore they are not sold everywhere.
SSD Benefits
An integral part of a modern computer is an SSD drive. What kind of device is it and how it works, we found out, it remains to highlight its main pros and cons compared to conventional HDDs. Let's start with the positive aspects of solid state drives.
The main advantage of SSDs is the incredible speed of reading and writing 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 gives faster programs and the operating system itself, which loads in seconds. This is very important, because the current generation of computers has high performance, which is greatly slowed down by the HDD. But with the advent of new drives, their speed has increased significantly.
The next advantage of SSD-devices can be called their higher resistance to external factors. They do not have such a fragile mechanism as those of hard drives. Thanks to this, they easily tolerate shaking, vibration and moderate impacts on the body. These devices will be an excellent solution for laptops. In addition, they cope better with temperature extremes.
Another advantage of the SSD is its noiselessness and low power consumption. Due to the fact that hard disks have moving mechanical elements, they emit a certain level of noise. In addition, in working order, the HDDs have a fairly high temperature, so coolers have to rotate in accelerated mode. But all these problems are deprived of SSDs that do not heat up, do not make noise, and consume less electricity.
disadvantages
Having appreciated all the advantages of SSDs, it remains to find out what weaknesses the SSD hard drive has. What are these flaws? The first of these is the high cost of such drives. Despite the simplicity of its design, the manufacture of flash memory chips and controllers is quite a costly affair. But do not be upset about this, because technology is constantly evolving, and gradually the price of these products decreases. After a couple of years, they may well be equal in price to the HDD.
After the first drawback, the second can be distinguished. Due to the high cost, SSDs have less capacity than hard drives. For example, the memory capacity of some HDDs is 8 TB, while SDDs have reached only 1 TB.
The memory of SSDs is short-lived, and after a certain number of rewriting cycles have passed, it fails. Although the current generation of these devices has a fairly large service line, you must be prepared for the fact that one day the drive will stop working, and it will be problematic to recover information.
I would like to add that the SSD does not tolerate power surges quite well. If after one of such voltage drops it burns out, then it will be impossible to obtain data. In the case of the HDD, a certain sector will fail in it, and most of it will remain intact, so that you can extract all the undamaged information.
What should I look for when buying an SSD?
Having studied the information about solid state drives, many users probably wanted to purchase this device for their computer. But do not immediately run to the store and take the first goods that turned up. Here are some tips to help you choose your SSD.
First you need to pay attention to the amount of SSD. What it is? In other words, this is the amount of built-in flash memory. The higher its value, the more information can be recorded. But you do not need to buy the most expensive products, because solid state drives are mainly used to install operating systems and applications on them, and the main place to store data is still the hard drive. Having equipped your SSD system with only 60-120 GB, you can achieve a significant increase in the speed of your computer.
An important role is played by the speed of reading and copying. The higher it is, the better, but it happens that the motherboard cannot reveal the full potential of the SSD due to the low bus bandwidth. It so happens that in old laptops or PCs it makes no sense to install fast drives, 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 after that go to the store. SATA3 interfaces have the highest bandwidth , and for outdated IDE ports, a special adapter is required for installing SSDs.
The most important component of any solid state drive is the controller. It is this detail that controls all the processes associated with the processing of information. The durability of the entire device depends on how well it will be made, so it is recommended to give preference to proven and well-established manufacturers. The leaders in production are SandForce, Marvell, Intel, Indilinx.
In the end, pay attention to the dimensions of the drive. For a PC, this is not so important, because you can install any SSD in the system unit, and laptops can cause problems.
Solid State Drive Fundamentals
After reviewing the reviews of users and experts, we can conclude that an integral part of a modern computer is an SSD-hard drive. What it is and how it works, we have already considered. Now you need to learn how to use it correctly. It may sound strange, but to understand all the advantages of SSDs, you need to follow a few simple rules.
No need to fill all available memory to failure. Many people neglect this rule, because SSDs have a considerable price, so users buy small drives and fully load them with the necessary and not very information. But we must remember that if you leave less than 25% of free space, then the speed of data processing will significantly decrease. The fact is that the more memory, the higher the number of free blocks where you can write data. When there is too little space, the information is distributed over the cells of neighboring blocks, and this leads to a decrease in performance.
It is worth remembering that using solid-state drives can significantly increase the speed of your computer, so it is recommended that you install the operating system, applications and demanding games on them. But as the main storage of information it is worth using HDD. It will be more economical and practical, because they can easily cope with playing audio and video files no worse than SSDs.
It’s best to have one of the latest operating systems installed on your computer. For example, Windows XP or Vista are poorly optimized for working with SSDs and do not support the TRIM command.