[CP2K:957] Some tests on Opteron cluster (strange???)

[Teodoro Laino]

On 17 Apr 2008, at 13:55, ilya wrote:

>
> Hi, All  !!!
>
> Finally. I've compiled it !!!
> Very nice program for QMMM MD.

Thanks
>
> I've performed some tests on our Sun Fire X2100 cluster of Dual Core
> Opteron 175 Processors.
>
> I compiled with Intel Fortran 10.1.011
> used MKL 10.0.2.018, FFTW3 3.1.2, OpenMPI 1.2.6
>
> Benchmarked on H2O-32 from tests/QS/benchmark
>
> Here the results (sorry for formatting)
>
>  n thread tot | n proc  /  n thread per proc | cpu time per proc, sec
> | wall time, sec |  speedup
> ---------------------------------------------------------------------- 
> ------------------------------------------------------------
>      1        |          1/1
> |                          1703  |     1705      |    1.00
>      2        |          1/2
> |                          3282  |     1734      |    0.98
>      2        |          2/1
> |                            961  |      962      |     1.77
>      4        |          4/1
> |                            555  |      556      |    3.07
>      4        |          2/2
> |                          1787  |      971      |    1.76
>      8        |          4/2
> |                          1014  |      564      |    3.02
>      8        |          8/1
> |                            349  |      349      |    4.89
>
> First of all setting OMP_NUM_THREADS=2 and running 1 MPI process per
> node makes performance worse (lines 2, 5 and 6) compared to 2 MPI
> processes per node (we have 1 dual core CPU per node).
> Is it normal? CPU time still doubles.
>
> And is it a normal scaling behavior? ( 4.89 on 8 procs is not very
> good. I know the system is small but anyway).

here is the answer to your question:
http://groups.google.com/group/cp2k/browse_thread/thread/ 
f2e33ea1d1a971ae

Teo

>
> Thanks.
> >