[CPMD-list] how to speed up on amd64 machines

[Juerg Hutter]

Hi

your additional information indicates that there is a
problem. However, we still need more information to
locate the problem.
In addition to Axel's advice and request,
please send the timing information from an output with
a full run.
In addition it would be helpfull if you could run your
example with the serial code and with the parallel code
for 1, 2, 4, 8 cpus.

regards

Juerg Hutter


----------------------------------------------------------
Juerg Hutter                   Phone : ++41 44 635 4491
Physical Chemistry Institute   FAX   : ++41 44 635 6838
University of Zurich           E-mail: hutter at pci.unizh.ch
Winterthurerstrasse 190
CH-8057 Zurich, Switzerland
----------------------------------------------------------


On Mon, 16 Apr 2007, Bin Pan wrote:

> Hi Prof. Hutter,
>
> I said that it is very slow because I used 6 CPU's on a Dual Core AMD
> Opteron(tm) Processor 870 connected by myrinet and compared the
> time required to finish one MD cycle with that done by 4 CPU's on a
> Intel(R) Xeon(TM) CPU 3.00GHz connected by ethernet for the same system.
> The first needs ~90 seconds, however the second only needs ~60.
> I expected the first one has faster CPU and better network connection.
>
> Are these enough info for you to give me some advice in how to
> improve the speed?
> Thanks a lot!
>
> Best regards,
> Bin.
>
> At 02:57 4/16/2007, Juerg Hutter wrote:
>> Hi
>>
>> you have to give us more precise information.
>> What exactly do you mean by 'it is very slow'.
>> Do you mean slow in general, e.g. compared to
>> another plane wave code or slow because
>> of bad speedups in parallel compared to the
>> serial runs?
>> You should also give us some information on your
>> computer. What is the exact version of your CPUs
>> and what is the type of your network?
>> At the end of each run CPMD prints timing information.
>> Please attach at least one such timing information
>> block for a run that you consider too slow.
>>
>> regards
>>
>> Juerg Hutter
>>
>> ----------------------------------------------------------
>> Juerg Hutter                   Phone : ++41 44 635 4491
>> Physical Chemistry Institute   FAX   : ++41 44 635 6838
>> University of Zurich           E-mail: hutter at pci.unizh.ch
>> Winterthurerstrasse 190
>> CH-8057 Zurich, Switzerland
>> ----------------------------------------------------------
>>
>>
>> On Sun, 15 Apr 2007, Bin Pan wrote:
>>
>>> Hi CPMD users,
>>>
>>> I am wondering how to speed up CPMD runs on amd64 cluster using MPI
>>> parallelization.
>>> Previously I compiled CPMD using pgi compiler with acml. However, I
>>> found it is very slow.
>>> The flags I used are:
>>>
>>> CPPFLAGS = -P -C -traditional -D__Linux -D__PGI -DFFT_DEFAULT
>>> -DPOINTER8 -D__pgf90 -DPARALLEL -DMYRINET
>>> CC = gcc -O2 -Wall -m64
>>> FC = pgf90 -c -fastsse -tp k8-64
>>> LD = pgf90 -fastsse -tp k8-64
>>>
>>> Can you please let me know how to improve the performance?
>>> Thanks a lot!
>>>
>>> Best regards,
>>> Bin.
>>>
>>> _______________________________________________
>>> CPMD-list mailing list
>>> CPMD-list at cpmd.org
>>> http://cpmd.org/mailman/listinfo/cpmd-list
>
>
>
> ---------------------------------------------------------------------
> Bin Pan
> Ph.D. Candidate
> Department of Chemical Engineering
> Massachusetts Institute of Technology
> Tel: 617-253-6675
> E-mail: binpan at mit.edu
> Room E19-528, 77 Mass. Ave. Cambridge, MA
> ----------------------------------------------------------------------
>
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