Path: news.mathworks.com!not-for-mail
From: "Steven Lord" <slord@mathworks.com>
Newsgroups: comp.soft-sys.matlab
Subject: Re: Matlab 2008b supports multithreading?
Date: Sun, 1 Mar 2009 12:53:08 -0500
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"Luna Moon" <lunamoonmoon@gmail.com> wrote in message 
news:dd951397-0927-4532-ae53-076291dfa083@40g2000prx.googlegroups.com...
> If I have Quad Core, with 4 cores,
>
> how much portion of Matlab 2008b now supports multi-threading?

Most of the functions that invoke LAPACK or BLAS, assuming the problem is 
large enough, and some of the elementwise functions.  [We don't offer a list 
of the functions.  We don't want users to avoid certain functions because 
they're not on the list -- they may support multithreading in a future 
release.]

This assumes you mean implicitly multithreaded, where you the user don't 
need to do anything special to enable the multithreading.  If you want to 
explicitly multithread your function, look at Parallel Computing Toolbox and 
MATLAB Distributed Computing Server.

> Without changing my previously coded Matlab programs, will I see a
> significant improvement?

This question is impossible to answer as stated.

If your previously coded MATLAB program is the following, it will not see 
ANY improvement.

function z = addup(x, y)
z = x+y;

If it tries to compute and work with the LU or QR factorization of large 
matrices, then you may see some improvement.

-- 
Steve Lord
slord@mathworks.com