[Pw_forum] a strange behavior for QE-v4 compared with QE-v3

[lan haiping]

thanks , Axel.
This scheme does work .
best

On Wed, Nov 26, 2008 at 4:29 PM, Axel Kohlmeyer <akohlmey at cmm.chem.upenn.edu
> wrote:

> this looks a lot like you are using two different versions
> of MKL for the two compiles and thus are another "victim"
> of the automatic threading of MKL v10. you should not
> have a process with >100% CPU with a regular compile.
> now if you have 8 cores and 8 MPI tasks and each of them
> threads across 8 cores, you have a) a severe overload of
> the scheduler and b) a big mess and all kinds of bad
> performance issues.
>
> try setting OMP_NUM_THREADS=1 and check if that
> changes the behavior.
>
> cheers,
>   axel.
>
>
>
> On 11/25/08, lan haiping <lanhaiping at gmail.com> wrote:
> > Dear Paolo,
> > thanks for explaination.
> > But this behavior  is really strange i have ever come to.
> > i have tried to rebuild the mpich and the QE, and nothing is
> > gained.   Another strange problem is  that the work i execute  parallelly
> > with QE-v4  sometimes come to idle without execuation or output
> > information.
> >
> > is there any other suggestion to figure what the problem with it ?
> >
> > thanks
> >
> > On Wed, Nov 26, 2008 at 1:55 AM, Paolo Giannozzi
> > <giannozz at democritos.it>wrote:
> >
> >> lan haiping wrote:
> >>
> >> > A strange  behavior is found for QE v4 when i carry out parallel
> >> > executation [...] But this situation doesnot happen when i try
> >> > to run the same work with QE-v3.
> >>
> >> it's hard to say anything meaningful based on the output of "top"
> >> and little more. There are several parallelization levles in QE,
> >> as explained here:
> >>
> http://www.quantum-espresso.org/wiki/index.php/Running_on_parallel_machines
> >> I don't remember what happened between v.3 and v.4, but whatever
> >> happened, it is unlikely to make parallelism less effective.
> >>
> >> Paolo
> >> --
> >> Paolo Giannozzi, Democritos and University of Udine, Italy
> >> _______________________________________________
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> >> http://www.democritos.it/mailman/listinfo/pw_forum
> >>
> >
> >
> >
> > --
> > Hai-Ping Lan
> > Department of Electronics ,
> > Peking University , Bejing, 100871
> > lanhaiping at gmail.com, hplan at pku.edu.cn
> >
>
>
> --
> =======================================================================
> Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
>  Center for Molecular Modeling   --   University of Pennsylvania
> Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
> tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
> =======================================================================
> If you make something idiot-proof, the universe creates a better idiot.
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-- 
Hai-Ping Lan
Department of Electronics ,
Peking University , Bejing, 100871
lanhaiping at gmail.com, hplan at pku.edu.cn
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