[Pw_forum] k-points parallelization in pwscf 4.2.1

Davide Sangalli davide.sangalli at gmail.com
Mon Feb 14 12:18:37 CET 2011

Thank you for the answer.

I did a check to be sure, but these jobs use only few MB of memory.
The serial run uses just 2.5% of my node memory (so around 15% for the 
run on 6 CPUs).
It does not seems to me that this could be the problem.
Moreover in the fft parallelization the memory was not distributed neither.

Is it possible that pwscf is not properly compiled?
Is there any other check that you would suggest to do?

Best regards,

      Largest allocated arrays     est. size (Mb)     dimensions
         Kohn-Sham Wavefunctions         5.68 Mb     (   6422,  58)
         NL pseudopotentials            13.33 Mb     (   6422, 136)
         Each V/rho on FFT grid          7.81 Mb     ( 512000)
         Each G-vector array             1.76 Mb     ( 230753)
         G-vector shells                 0.09 Mb     (  12319)
      Largest temporary arrays     est. size (Mb)     dimensions
         Auxiliary wavefunctions        22.73 Mb     (   6422, 232)
         Each subspace H/S matrix        0.82 Mb     (    232, 232)
         Each <psi_i|beta_j> matrix      0.12 Mb     (    136,  58)
         Arrays for rho mixing          62.50 Mb     ( 512000,   8)
      writing wfc files to a dedicated directory

On 02/14/2011 11:34 AM, Paolo Giannozzi wrote:
> Davide Sangalli wrote:
>> What could my problem be?
> the only reason I can think of is that k-point parallelization doesn't
> (and cannot) distribute memory, so the total memory requirement will
> be npools*(size of serial execution). If you run on the same node six
> instances of a large executable, memory conflicts may slow down more
> than parallelization can speed up.
> P.

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