On Thu, 2006-11-09 at 20:53 +0100, Clemens Fruhwirth wrote: > At Thu, 9 Nov 2006 15:22:54 +0100, > "Marco Costa" <costa.marco@xxxxxxxxx> wrote: > > > > Hi! > > > > On 11/9/06, Gerald Hopf <dm-crypt@xxxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > I am currently using AES-128 encryption and am able to get about 31MB/s > > > sustained performance on my single-core athlon 64 3000+ (when copying > > > from the encrypted volume to a fast non-encrypted volume). > > > > > > Since 31MB/s is will below the limits of gigabit ethernet, i would like > > > to get even more performance :-) > > > > It seems that you are already on the hardware limit of the harddrive. > > The overhead of encrypting your filesystem is very tiny. > > I may be wrong, though. ;-) > > That's completely wrong. You are not even close to the hardware limit, > > /dev/hda: > Timing buffered disk reads: 168 MB in 3.03 seconds = 55.48 MB/sec > > (regular 7200rpm disk) > > Even worse, you are not even close to the processors encryption speed > limit: > > type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes > aes-128 cbc 76228.13k 78740.37k 81087.48k 80974.17k 81265.19k > > I happen to have the same processor as Gerald, and 81mb/s is the > encryption speed for 128 bit key AES in CBC mode. > > To answer the original question: dual-core will not improve your > dm-crypt performance (at least for now) because there is only one > kcryptd thread per device. This might change with the workqueue stuff > that is about to be merged. I'm not following that development. Aha1 That would explain my improvements then. With relatively the same drives (maxtor 250gb max9s vs 160gb sata) I went from a very poor 21mb/s on my old overclocked xp1800/512mb to a pretty blistering (I think) 71mb/s on my e6300/1gb system. Perhaps the great improvement is due to the three disc RAID5 structure I use for the encrypted user partition... one thread per device actually means something there. Perhaps I need to invest in a dual cpu motherboard and go for 4 cores when I get my new 5 disc/1tb raid going! --------------------------------------------------------------------- dm-crypt mailing list - http://www.saout.de/misc/dm-crypt/ To unsubscribe, e-mail: dm-crypt-unsubscribe@xxxxxxxx For additional commands, e-mail: dm-crypt-help@xxxxxxxx
