Thanks for the quick reply -- we ran your test on our system, and found similar results. The CPU load issue was tracked down to a faulty CPU monitor -- even when using 8 threads on a 4 core HT machine, the CPU monitor reports 50% max usage for some unknown reason at this time.<div>
<br></div><div>Thanks again!</div><div>dennis<br><br><div class="gmail_quote">On Thu, Aug 26, 2010 at 1:05 PM, Jason Garrett-Glaser <span dir="ltr"><<a href="mailto:darkshikari@gmail.com">darkshikari@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><div></div><div class="h5">On Thu, Aug 26, 2010 at 11:28 AM, Dennis Munsie <<a href="mailto:dmunsie@gmail.com">dmunsie@gmail.com</a>> wrote:<br>
> Hi --<br>
> Does x264 have any support for detecting that it's running on a<br>
> Hyperthreaded enabled CPU and to only spawn threads for each real CPU? I've<br>
> noticed that on our quad core i7s, we've seen a total of 9 threads when<br>
> doing slice based threading (for low-latency support) when encoding a 720p<br>
> clip. Since the load on the machine appears to be 50% overall and it<br>
> doesn't get slower when we turn off HT, it appears those extra threads are<br>
> unable to get the resources to actually run in parallel with the 4 other<br>
> threads.<br>
> I am using x264 as a library in my own program -- so it may be that I've<br>
> just missed a configuration option that I should've set.<br>
> Thanks!<br>
> dennis<br>
<br>
</div></div>Our testing strongly suggests that the number of virtual cores is<br>
optimal when using sliced threads, even when HT is on:<br>
<br>
<a href="http://saintdevelopment.com/benchmarks/bfs-vs-cfs/720p_i7/2.6.32-720p-0lat-vf-nob.png" target="_blank">http://saintdevelopment.com/benchmarks/bfs-vs-cfs/720p_i7/2.6.32-720p-0lat-vf-nob.png</a><br>
<br>
Dark Shikari<br>
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</blockquote></div><br><br clear="all"><br>-- <br>dennis<br>
</div>