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From: Mark Geisert <mark AT maxrnd DOT com>
Subject: Re: cpu usage capped?
Date: Wed, 5 May 2010 04:29:15 +0000 (UTC)
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> I have some code that takes advantage of 8 cores on my machine using
> OpenMP. Under plain ol windows, this code causes all the CPUs to max
> out at 99%. But when recompiled for cygwin, each core jumps to about
> 85%. The rest is not being used by other processes. Could someone
> explain why this is the case?

Obviously, Cygwin gets the job done with less CPU utilization, handing you back
15% of your machine.  And you're complaining?

..mark

P.S. A more helpful response can likely only occur if you spell out more
specifically which varieties of apples and oranges you're comparing.  For
starters: "plain ol windows", is that MSVC or MinGW?  Is disk I/O involved? 
What OS and environment (e.g., VM? TS?).  I'm pretty sure I'm only scratching
the surface here.  We don't know what your code does other than use OpenMP.


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