What you need to know about SSD drives from the point of view of repair center employees
What you need to know about SSD drives from the point of view of repair center employees
Anonim
What you need to know about SSD drives from the point of view of repair center employees
What you need to know about SSD drives from the point of view of repair center employees

Who, if not the employees of repair centers, know all the features of the operation of an SSD drive. Therefore, the editor of "MacRadar" took the phone and called several centers from the top ten results of Google. In the process of talking with the masters, we managed to formulate three basic rules for using SSDs.

The 25 percent rule

Rule one: leave 25% of the SSD drive empty. For example, you bought a 120 gigabyte SSD. About 10 gigabytes will go to the OS, another 25 gigabytes should remain empty. We get 82.5 gigabytes. This is the disk space that we can use. Great, isn't it? We buy a 120 gigabyte disk, but we can only use 82, 5. What explains this?

“If the disk is completely filled with data, for example, movies, music and left free, say, 5-10 gigabytes, then the disk will start to“dull”, - says Nikita Provotorov from ON-PC.ru company. - This happens with disks of any company: INTEL, Silicon Power, ADATA and so on. Therefore, it is recommended to leave 15-25% of the disk space free."

“The 25% rule can be considered empirically useful,” says a well-known Russian data recovery expert. Ilya Seidel … - The higher the write and rewrite rate on the SSD, the more empty space should be left. More importantly, avoid excessive heating of SSDs. The reliability of flash memory decreases with increasing temperature. The SSD controller takes that into account, but why make life difficult for it? And, of course, you do not need to keep data frequently updated in auto mode on the SSD, for example, 1C databases. If this is a production need, then take a PRO-class disc and check the daily recording volume with the manufacturer's specification. Then the guarantee will be valid."

The drop in the speed of a fully-filled SSD disk is due to the peculiarity of the memory cells. Each block of information is 512 kilobytes, and there can be, for example, only one page of 4 kilobytes in size. But in this case, the entire block of information will be considered occupied. Unlike HDD, in which new data can be added to existing ones or written over old ones, data in SSD is first read and then written over the new one. This leads to a slowdown in the speed of work. To maintain the speed of an SSD, you need to regularly "remove garbage" from it, and for this there is a TRIM function.

TRIM Rule

The cells of the SSD-disk are filled with data blocks and require preliminary cleaning before writing new information. A special TRIM command tells the SSD controller that the data in certain cells was really deleted by the user and is no longer needed. During pauses, the controller will clear the cells in advance, that is, it will simply "remove garbage" from the data. This has a positive effect on the speed of the drive and its lifespan. The latest OS X 10.10.4 update added TRIM support in third party SSDs. To enable it, enter the sudo trimforce enable command in the Terminal and restart the computer. TRIM is enabled.

Backup rule

"Recovering data from an SSD is model dependent and not always possible," says Valery Dorogavtsev from the company MHDD.ru. - If the SandForce 3 controller is installed on the disk - and these are the latest models of Intel, OCZ, Kingston disks - then we can say with a high degree of confidence that information from them will not be able to be recovered."

“99.99% of the disks on the SandForce controller are not recoverable,” emphasizes Vlad Barkhaev from the DATARC company. "And if you use disks on a Marvell controller, for example, from Plextor, then most of the time you can recover the information."

“SandForce controllers use hardware encryption,” explains Pavel Horuzhy from the FixInfo company.- In theory, any encryption can be broken, but since it uses a 256-bit key, the cost of breaking is very high. That is why they say that it is impossible to recover information from an SSD disk”.

"The easiest way to recover archived data," clarifies Nikita Provotorov … - The fact is that when creating an archive, a recovery code is written, and in the future, using the archiver, you can correct errors with less loss of packed data.

And in conclusion - the recommendation of all surveyed service center masters: be sure to make a backup. Unlike HDDs, which can take a long time to die, SSDs break down suddenly and permanently.

Recommended: