Re: How to speed up Octave

[Trond Eivind Glomsrod]

"John W. Eaton" <address@hidden> writes:

> On 19-Jun-2001, Laubach, Mark (Nicolelis Lab) <address@hidden> wrote:
> 
> | Inspired by the recent thread titled "Octave / Win 2000 memory 
> limitations", 
> | I ran a few tests of execution speed for Octave (2.0.16, from the Mandrake 
> | install disks) under Linux (Mandrake 8.0) and Windows (Win2k), and Matlab 
> | (version 6) under Windows.  I was disappointed to see how slow Octave is 
> | compared to Matlab on my home PC (Athlon 700 MHz with 256 MB SDRAM).  (I 
> | obtained a similar pattern of results on my (slower) notebook.)  Can 
> someone 
> | please suggest how I might improve execution speeds for Octave, especially 
> | under Linux? 
> | 
> | The tests I ran were:
> | 
> | tic;A=rand(20,20000);B=svd(A);toc
> | tic;A=rand(2000,2000);B=prod(A);toc
> | tic;A=rand(1000,1000);B=inv(A)*A;toc
> 
> I believe all of these operations involve calls to lapack and/or blas
> libraries.  If you use a recent development version of Octave linked
> with the atlas libraries, then you will probably see some improvement.

I just tried this on a Dual PIII 733 system, 256 MB RDRAM with Red Hat Linux 
7.1 and atlas
configured for this machine ("make config" run locally, standard options except 
don't use
-omit-frame-pointer and  add "-march=i386 -mcpu=i686"), gcc 2.96RH.

- the first test was on average 14% faster with Atlas. In the second test, 
atlas didn't matter. 
The third test was the only one showing a real gain: Just above 40% faster with 
Atlas.

-- 
Trond Eivind Glomsrød
Red Hat, Inc.



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