Re: [ESPResSo] Espresso performance with gcc 4.3

[Axel Arnold]

On Monday 17 August 2009 12:57, Mehmet Sayar wrote:
> Hi everybody,
>
> I am having some trouble with performance of Espresso which is compiled
> with gcc 4.3. At least that is my best guess regarding the origin of the
> problem.
>
> I have a couple of 8-core machines with Suse 10.2 installed. I recently
> updated one of them to Suse 11.1. The machines have exactly the same
> architecture. Under Suse 11.1 Espresso's performance is more than 10 times
> slower.
>
> Gromacs displays the same problem.
>
> When I look at the common libraries between Espresso and Gromacs, I suspect
> either the gcc or the lamd installations as the source of the problem.
>
> However I tested the performance of Espresso with mpi-fake. And the
> performance is still terrible under Suse 11.1. That leaves gcc as the only
> candidate.

Hi!

gcc 4.3 or actually OpenSuSE 11.1 should also not be the problem, because I 
have a machine with it where Espresso works fine. So, seems more like a 
problem with OpenSuSE 11.1 on your hardware... It could be some problem with 
the NUMA e.g. . However, I cannot really tell how you can check that.

Axel

-- 
Dr. Axel Arnold 
Fraunhofer SCAI
Schloss Birlinghoven, 53754 Sankt Augustin, Germany
Tel: +49 2241 14 2575