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From: "fabio freschi" <fabio.freschi@remove.gmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: multithreading with chol
Date: Tue, 23 Jun 2009 13:55:03 +0000 (UTC)
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Hi all,
I have found a strange but absolutely fine behavior of chol function. It seems that chol can gain speed when multithreading is enabled. I do not have the access to data of my 8 cores linux machine, but also on my intel MACBOOK the factorization of a sparse matrix coming from a scalar poisson problem is faster. Some data
*Matlab 7.5.0 (R2007b)
*size(A) = 125000x125000
*nnz(A) = 1815598
*metis preordering (from SuiteSparse, thanks Tim Davis!)
chol with multithread (2 cores) -> 20.51 sec
chol w/o multithread -> 27.44 sec

This can be extrapolated for a 1.6Mx1.6M matrix on a 8 cores machine...
These results are not in accordance with "Muli-threaded performance and Cleve's Corner" on cholmod webpage. Any ideas?
thanks
fabio