Hi!
On Thursday 08 July 2004 00:14, Steven M. Schultz wrote:
> Hype(r)Threading (it's mostly "hype" by Intel) is not the same
> as actually having a 2nd cpu.
Not the same, sure. That's why I wanted to see the difference :-)
> > So, the results show that encoding with hyperthreading enabled is about
> > 10% faster and the optimal thread number for uniprocessor P4 system
> > without
>
> I've very suprised to see those results! When I enabled HT the
> entire system slowed down and encoding ran about 15-20% *SLOWER*. That
> was on a real dual P4/Xeon. With HT enabled the system showed
> 4 "cpus" (of which only 2 were the real/heavy ones and 2 were the
> partial/lightweight ones). The kernel treated all 4 pretty much
> the same and scheduled processes accordingly - and that is something
This was a 2.4.x kernel from the kernel.org? I'm not using them since a long
time because they really SUCK compared to RedHat kernels.
RedHat's 2.4.x kernels have a big set of features from 2.6.x kernels: they are
low-latency, preemptive, have NPTL threads etc. And they know difference
between real SMP system & system with hyperthreading and shedule processes
differently. This can explain the difference.
> Place a yuvdenoise, yuvmedianfilter, or y4mdenoise in the pipeline and
> see what happens :-)
BTW, it will be really interesting - what will be the difference in this case,
than processor has more different tasks to run? Can you propose additions to
my command line ("cat stream.yuv | yuvscaler -n n -O SVCD 2> /dev/null |
mpeg2enc -f 4 -F 1 -p -M <thread number> -o stream.m2v 2> /dev/null") to
test?
> Oh, you're not running the CVS version. That's where changes/fixes
> would be made if bottlenecks/bugs are found and fixed as a result of
> testing/profiling/etc...
Ok, I'll try with CVS version also.
Alexei
-------------------------------------------------------
This SF.Net email sponsored by Black Hat Briefings & Training.
Attend Black Hat Briefings & Training, Las Vegas July 24-29 -
digital self defense, top technical experts, no vendor pitches,
unmatched networking opportunities. Visit www.blackhat.com
_______________________________________________
Mjpeg-users mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/mjpeg-users
