SSD performance drops with TrueCrypt

A

Alexey2012-02-11 22:46:08

Solid State Drives

Alexey, 2012-02-11 22:46:08

I installed a new Corsair Force GT 120 Gb disk in my laptop , although it claims 500 MB per second, the figure is clearly 2 times too high. AS SSD showed 150 MB per second for writing, 230-250 MB per second for reading. However, this greatly accelerated Windows and I was satisfied (according to the puzomer 7.6 points per disk from the second time, at first it was 7.9). The system was transferred ready, everything works fine.

Then I fully encrypted the system drive using TrueCrypt, everything is just fine and works. The AES algorithm is used for encryption, supported by the hardware of the processor, according to tests, it produces more than a gigabyte per second in memory.

However, performance in AS-SSD with the TrueCrypt driver dropped quite a lot. For writing a maximum of 110 MB per second, for reading a maximum of 200 Mb per second. About all sorts of random reads / writes - generally sadness. The access time increased by 4 times, from 0.1 ms to 0.475 ms. IOPS also dropped by a factor of 4-5.

This is very sad. Maybe there are some settings somewhere that something depends on?

PS in Windows all caching is enabled, the laptop has 8 gigs of RAM, win 7, trim and all that works. In SATA2 mode. The disk has the latest firmware. All drivers, etc. there is. During the test, there is no load on the percent.

What am I doing wrong?

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5 answer(s)

A

Alexey Sundukov, 2012-02-12
@alekciy

>In SATA2 mode.
>What am I doing wrong?
You're using the wrong tire. And "230-250 mb" just say that everything rested on the bus.

A

Alexander Belugin, 2012-02-11
@unkinddragon

Here they write that trim operations do not reach the SSD itself, as well as performance comparison graphs.

B

blackarrow, 2012-02-11
@blackarrow

at office This problem periodically pops up in the truecrypt forum, for example, there are other discussions here .

I

INSTE, 2012-02-12
@INSTE

Many SSDs are tricky and use built-in compression to increase speed. Of course, benchmarks work fine (zeros are compressed ok!), but encrypted data makes the disk sad (one of the NSA requirements for AES was a nearly zero compression ratio for compressed data). For
the same speed, you need to compress to encrypt (NTFS compression?).

@

@ntkt, 2012-02-12
_

And what is the encryption speed for the selected mode shown by the Truecrypt benchmark?
For example, for a 4-core 3 GHz Core i5 without hardware AES = 260 MB / s for 4 threads. How many threads the driver will use in practice is unknown.
We will not lose in the final speed only if the write speed is obviously less than the encryption speed.