[CPMD-list] Empty ENERGIES file on x86-64 systems

[Axel Kohlmeyer]

On Sat, 6 May 2006, Alexandr Isayev wrote:

AI> Dear CPMD community.

dear alex,

AI> I have experienced strange behavior of the code under AMD x86-64 architecture.
AI> The file ENERGIES during *any* MD run always remains empty (0 bytes). Affected systems are
AI> Opteron Linux cluster [cpmd v 3.9.2 compiled with pgi 6.1] and Cray XT3
AI> [cpmd v 3.11.1 compiled with pgi 6.1.1 respectively]. I am also
AI> checked the the reference energy values from cpmd-test distribution.
AI> The values are correct.

that is ok, if it happens during the simulation, since the file is
kept open. if the job is terminated regularly, you should still get
all the data in it. due to keeping the file open and not flushing
it, it should give a better performance. especially on the cray xt3
this is _essential_. in that specific machine in general, it helps
a lot to also increase the i/o buffer size and hack the code so it
won't write GEOMETRY/GEOMETRY.xyz in every step.

on what xt3 are you running on? i might have some extra hints
for you to get even more out of it...

best regards,
    axel.

AI> 
AI> Does anyone encountered something like that?
AI> 
AI> Thank you in advance,
AI> Alexandr
AI> 
AI> 
AI>   
AI> 
AI> -------------------------------------------------------
AI> Alexandr Isayev,
AI> Graduate Research Assistant, and System Administrator
AI> @ Computational Center for Molecular Structure
AI> and Interactions (CCMSI),
AI> Jackson State University,
AI> Jackson, MS USA
AI>    Tel:  +(601) 979-1134
AI> e-mail:  alex(at)ccmsi.us
AI>    Web:  http://www.ccmsi.us
AI> --------------------------------------------------------
AI> 
AI> _______________________________________________
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AI> CPMD-list at cpmd.org
AI> http://cpmd.org/mailman/listinfo/cpmd-list
AI> 

-- 
=======================================================================
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
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