| SSD ar gadiem paliek lēni. |
[Jan. 14th, 2021|11:09 am] |
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Steve Gibson of grc.com 2 has just released a free tool ReadSpeed. Using it to measure the speed of SSDs, early adopters have discovered some interesting but little known facts about how they age.
To explain, a little background. In order to achieve a high storage capacity at low cost, modern SSDs (except expensive enterprise variants) use Multi-Level Cell (MLC) technology. Instead of each storage cell recording a 1 or a zero with full or empty charge, they charge each cell to one of 8 or more voltages, representing 3 or more bits. But with static data (such as operating system files) written once on installation and then read many times, the voltages in individual cells can drift, causing errors. This is accepted, and the SSD will hide it by using sophisticated error correction codes to recover the data, even though the raw data read from the cells contains errors. But it does mean that read operations will slow down because of the computing overhead of the error correction. And eventually, the errors are likely to accumulate to a level beyond which the error correction can work.
What ReadSpeed has shown is that some brands of SSD report markedly slower read times, sometimes drastically slower, for the start of the drive where most of the static operating system files are located. In these cases, another tool Spinrite from grc.com 2 can force the SSD to reallocate tired storage, resulting in a marked increase in speed.
From tests that people have done it appears that Samsung is one brand of drives which are particularly resistant to this form of aging. A few years ago I got an Intel SSD for my previous laptop, thinking that was bound to be a good brand. But when I tested it recently I found it had indeed slowed down in some areas. But after running Spinrite it was 25% or more faster!
ReadSpeed is free (though Spinrite isn’t). You can read about it and download it from https://www.grc.com/readspeed.htm |
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