Re: [ESPResSo] Espresso performance with gcc 4.3

[Mehmet Sayar]

Hi Axel,

That is quite bad.

What ever the problem is, it is not platform specific either.
Now I reproduced the same poor results on an Dual core AMD Opteron machine (the 
other was a Xeon 8-core).

Mehmet

Axel Arnold wrote:
> 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

--
Mehmet Sayar - Assist. Prof.  Koc University
Email:address@hidden        Dept. Mechanical Eng.
Phone:+90-212-338-1840        Rumelifeneri Yolu, Sariyer
Fax:  +90-212-338-1548        34450 Istanbul, Turkey