On Wed, Mar 06, 2002 at 11:14:59PM +0200, Jari Ruusu wrote: > > Tested on 2.4.18 kernel, Pentium-2 300 MHz, ST34342A IDE disk > > Implementation Cipher Total CPU cycles spent in system mode > -------------- ------ ------------------------------------- > cryptoapi AES-128 54 % > loop-AES AES-128 36 % > cryptoapi serpent-128 81 % > loop-AES serpent-128 78 % > > All above implementations used the disk at maximum data transfer rate > supported by the disk, so megabytes/sec rate was same for all ciphers on > unloaded test box. > > Serpent implementations used same cipher source code. Cryptoapi overhead on > loop encryption seems to be few percent of CPU cycles. That's strange. So AES does much more in user-mode than serpent does? So that's why serpent's run time is dominated by system-mode cpu cycles whereas AES is not? Why is that? What part is running in user-mode out of curiosity? And why is there such a large discrepancy between cryptoapi's AES CPU time and loop-AES's AES CPU time? Context switching? - Steve Weigand (weigand@texas.net) Austin, Texas USA http://weigand.home.texas.net - Linux-crypto: cryptography in and on the Linux system Archive: http://mail.nl.linux.org/linux-crypto/
