Liping, Of course, my tests were made on 8 CPU cores.
Huiqun Zhou @Nanjing University, China ----- Original Message ----- From: "Liping Yu" <[email protected]> To: "PWSCF Forum" <pw_forum at pwscf.org> Sent: Tuesday, February 24, 2009 9:49 PM Subject: Re: [Pw_forum] Use of pool > Dear Huiqun, > > If your results are based on the same number of processes for different > npools, they make sense to me. To my understanding, the almost linear > time scaling of using npool means that the computer time is almost > linear to npool (and also the total number of procs) only when we fix > the number of the processors at each pool. > > Please correct me if I am wrong. Thanks! > > Liping Yu > Department of Physics > NC State University, USA > > > Huiqun Zhou wrote: >> Dear list users: >> >> I happened to test duration times of calculating the system I'm >> investigating against number of pools used. There are totally >> 36 k points. But the results surprised me quite a lot. >> >> no pool: 6m21.02s CPU time, 6m45.88s wall time >> 2 pools: 7m19.39s CPU time, 7m38.99s wall time >> 4 pools: 11m59.09s CPU time, 12m14.66s wall time >> 8 pools: 21m28.77s CPU time, 21m38.71s wall time >> >> The machine I'm using is an AMD box with 2 quad core shanghai. >> >> Is my understanding of usage of pool wrong? >> >> Huiqun Zhou >> @Nanjing University, China >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
