[dm-crypt] LUKS & TrueCrypt - Speed Test
jorge.fabregas at gmail.com
Thu Jul 28 15:07:22 CEST 2011
On 07/28/2011 01:11 AM, Arno Wagner wrote:
> There is an old gemran egineering saying:
> "wer mist mist mist"
> (along the lines of "Those who measure measure crap")
> I think it applies here.
I warned everyone that this wasn't a pro test :) At least, I laid down
the specifics involved.
> Real-time is tricky. It does not reflect effort invested. If you
> look at the sys itime, you see that the crypto-effort is only about
> 90 seconds more. Even that is pretty much below the measurement
I agree here. I shouldn't have paid much attention to real time.
Nonetheless I'm still curious about the little difference...
> Very likely the differences are due to storage differences
> and do not show crypto-speed differences.
I used the same external drive for both tests.
> I suggest you run both tests at least 3 times and make sure
> your storage is significantly faster than the crypto, e.g.
> by doing this between RAM disks or SSD storage. Also a complex
> disk access patterhn like rsync is not suitable as it may
> have complex interactions with caching and buffering.
I didn't want to go with sequential & random read/writes (with different
block sizes etc) as I wanted a rough test out of the very same tool I
use every day (rsync) with the same data on the same disk. I understand
the crypto involved (CPU-wise) is much faster than the slow I/O of my
external drive but that's what I have. Regarding repeating the test, I
totally agree with that.
Thanks for the input.
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