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From: Chris Stanley <>
Subject: Max 50% usage on dual-core CPU
Date: Mon, 12 Nov 2007 20:33:00 -0000	[thread overview]
Message-ID: <> (raw)

I'm working with ffmpeg which uses Pthreads-w32 in Windows XP Pro SP2. 
I've used both Pthreads-w32 2.8.0 and 2.9.0 (which as far as I can tell 
doesn't exist, but is bundled with the Celtic Druid ffmpeg binaries 

When using a single-core system (Celeron 2.5Ghz), everything is fine and 
ffmpeg/Pthreads-w32 eagerly uses 97-99% of my CPU.  But when I move the 
same code to a dual-core system (P4 3Ghz), it will never exceed exactly 
50% of the CPU.  By default it uses both cores at about 20/30.  If I 
change the affinity and restrict it to one core, then it uses the whole 
thing but again won't exceed exactly 50% of the total CPU.  I get the 
same results reading from and writing to a flash drive, so I don't think 
it's an I/O bottleneck.

I'm posting this to the ffmpeg list as well, but it seems like this 
could be something related to Pthreads-w32.  Does anyone have any 
thoughts about what might be going on?



Chris Stanley

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             reply	other threads:[~2007-11-12 19:58 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-11-12 20:33 Chris Stanley [this message]
2007-11-15 19:22 ` Chris Stanley

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