about latest versions

[Michael Goffioul]

On Sat, Apr 18, 2009 at 1:45 PM, MHELHEFNY <mhelhefny at gmail.com> wrote:
>
> ----- Original Message -----
> From: "Tatsuro MATSUOKA" <tmacchant at yahoo.co.jp>
> To: "Michael Goffioul" <michael.goffioul at gmail.com>; "MHELHEFNY"
> <mhelhefny at gmail.com>
> Cc: <bug at octave.org>
> Sent: Saturday, April 18, 2009 4:16 AM
> Subject: Re: about latest versions
>
>
>> Hello
>>
>> Benjamin's octave-mingw will check cpu and sse2 and sse3 versions of the
> ATLAS exist.
>> In my computer in my my uinversity, the cpu of which is presscotte
> (pentium4-HT 3.4GHz),
>>  the following test have given,
>>  n=2000; A=randn(n); B=randn(n);tic; C=A*B; t=toc, MFLOPS=2*n^3/t*1e-6
>>  Benjamin 3.0.2 (mingw)  MFLOPS = 1973.0
>>  Michael  3.0,3 (MSVC)   MFLOPS = 1845.9
>>
>> The results were almost the same.
>>
>> I do not think that Atlas of Benjamis's Octave is optimized for the older
> CPUs.
>>
>> As a refrence, in case of self build Atlas for my computer (octave-3.0.4)
> using
>> mingw(gcc-4.3.2-dw2-TDM)
>> MFLOPS = 4830.2
>> If you want to get highest performance for matrix calculation, the octave
> will be reccomended to build
>> by yourself with the optimized the ATLAS (or GotoBLAS*) for you computer
> system.
>> However it is hard way to the beginners.
>>
>> *GotoBLAS can be used for the self building case because its licesence is
> not compatible the GPL.
>>
>> Regards
>>
>> Tatsuro
>>
>
> Hello
>
> as  you said on your cpu (pentium4-ht 3.4GHZ) the results were almost the
> same. but alas on my cpu (pentium4 2.8GHZ) the results were different
>
> Benjamin 3.0.2 (mingw) MFLOPS = 3580.4
> Michael 3.0.3 (MSVC)   MFLOPS =318.25
>
> which is 12 times better with mingw both versions was ready on the web. on
> my computer , ver. 3.0.2 is even better two folds than on yours. That is
> very strange.

The version 3.0.3 you installed does not use ATLAS, but basic
unoptimized BLAS/LAPACK. Try to re-install and at early stage,
select the right CPU.

Michael.