Subject: Re: AMD Geode LX Security Block (was Re: NetBSD on the Soekris net5501 status report)
To: Jared D. McNeill <jmcneill@invisible.ca>
From: Jack Lloyd <lloyd@randombit.net>
List: tech-crypto
Date: 06/18/2007 09:22:24
On Mon, Jun 18, 2007 at 08:56:01AM -0400, Jared D. McNeill wrote:

> 	Doing aes-128-cbc for 3s on 8192 size blocks: 9972 aes-128-cbc's in  
> 0.01s

In that case your timing results may be off by a significant
amount. OpenSSL is probably using times(2) to measure process CPU
time, however since all the real work is being offloaded to a card
there is very little to report. So when OpenSSL calculates the
performance using work_done / time_used, the numbers come out too
large. It would be better here to use wallclock time (clock_gettime or
gettimeofday), which will more accurately measure the true throughput.

-Jack