On Thursday 24 August 2006 13:09, 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 > [EMAIL PROTECTED]:/usr/obj/usr/src/sys/WKS02_SMP amd64 > > Does anyone could explain me what's happening with my system ?
An application that is not written to take advantage of a multi-cpu system is unable to max out more than one CPU at a time. top isn't really SMP 'aware' so in a dual CPU system something that is using 50% of the CPU is in reality maxing one CPU. This is a bit over-simplified because the process will bounce between the two CPUs but it will never execute on more than one at a time. -- Thanks, Josh Paetzel _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
