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

[Laurent C]

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 ?

-- 
Laurent C.