[AMD64-SMP] I can't get my cpus working at 100%

Kris Kennaway kris at obsecurity.org
Thu Aug 24 19:06:57 UTC 2006


On Thu, Aug 24, 2006 at 08:09:35PM +0200, Laurent C wrote:
> Hello all,
> 
> I can't get my athlon x2 processor working at 100% on cpu-intensive apps.
> I've made some tests with "john --test" and "transcode", wich are both
> multithreaded apps.
> 
> For example if I launch transcode it takes between 50% and 55% cpu (on top),
> and if I launch
> a second transcode session on another file, the total cpu used on top is
> 100%, without lower the speed
> of the first transcode session.
> 
> The same behavior occurs with john. A single "john --test" give me some
> speed results, and the same
> command with a transcode or second "john --test" give me the same speed
> results but now with 100%
> cpu used.
> 
> I made a "portupgrade -auf" just after building and installing my SMP kernel
> and World, to be sure all is up-to-date.
> 
> So it's seems it's not a "top" output problem, but a real underuse of the
> computing power.
> 
> %uname -a
> FreeBSD wks02.chez.oim 6.1-STABLE FreeBSD 6.1-STABLE #0: Thu Aug 17 18:47:31
> CEST 2006     laurent at wks02.chez.oim:/usr/obj/usr/src/sys/WKS02_SMP  amd64
> 
> Does anyone could explain me what's happening with my system ?

How do you know the applications are running with two threads?
Presumably you need to specify the amount of parallelism.

Kris
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