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Re: openmp
From: |
skaller |
Subject: |
Re: openmp |
Date: |
Mon, 15 Oct 2007 15:43:30 -0000 |
User-agent: |
Pan/0.129 (Benson & Hedges Moscow Gold) |
On Sat, 13 Oct 2007 20:30:52 -0700, Paul Pluzhnikov wrote:
> skaller <skaller@users.sf.net> writes:
>
>> So which version of g++ first provides openmp support?
>
> From http://gcc.gnu.org/gcc-4.2/changes.html:
> OpenMP is now supported for the C, C++ and Fortran compilers.
hum ... well I tried this on my amd64x2 machine. A test case
for LU decomposition, dimension 800:
1 thread: 4.7 seconds
2 threads: 13 seconds
Well then I discovered the stupid program was using 'clock()' function.
Which counts the time for BOTH processors!
So I used the time command .. and the threaded version is STILL slower.
BTW: running Linux rt patched kernel..
--
John Skaller <skaller at users dot sf dot net>
Try Felix, the successor to C++ http://felix.sf.net
- openmp, skaller, 2007/10/14
- Re: openmp, Paul Pluzhnikov, 2007/10/14
- Re: openmp,
skaller <=