crypto accelaration

[hausschuh]

Ok - time has passed by.
My kernel is "2.6.32-5-kirkwood" and I use dm-crypt/luks.

Testing an external USB Disk I get:

Timing buffered disk reads: 92 MB in 3.05 seconds = 30.15 MB/sec

testing the unecrypted partition on this disk.

And

Timing buffered disk reads: 24 MB in 3.26 seconds = 7.37 MB/sec

testing the mounted encrypted partition of this disk.

How do I find out whether hardware acceleration is in use or not?

[FrankL]

Debian squeeze (kernel 2.6.32-5-kirkwood) on a kirkwood platform using dm-crypt/luks:

all writes to exact same location on an internal SATA notebook drive, and around 3GB (+/- 100 MB)!

Write unencrypted	39.8MBps
(partly) accelerated ciphers:
Write -c aes-cbc-essiv:sha256 -s 256	7.9MBps
Write -c aes-cbc-plain -s 256	9.1MBps
Write -c aes-cbc-plain -s 128	9.2MBps
non-accelerated ciphers:
Write -c blowfish -s 128	9.3MBps

I do not know how to run dm-crypt with a dummy cipher (-c cipher_null or -c compress_null do not seem to work), so the comparison with the plain disk speed is apples to oranges.

When I run openssl speed blowfish aes-128-cbc, it shows that blowfish is about twice as fast (when using no acceleration for either cipher).