[Pw_forum] parallel computation too slow

Elie M elie.moujaes at hotmail.co.uk
Mon Mar 19 14:45:09 CET 2012


Professor Giannozzi,
Thanks for the reply. The CPU time is 1 hr 26 min (2hrs 2 min normal time) for the scf calculation on the nodes (3 of them). If I have 42 atoms then this is equivalent to almost 8 days CPU time or 10 days normal time. Four days have passed and I am still in representation 6 out of 126 which i guess is not the normal situation...Can anything be done  (or checked) in this case?
Regards

Elie
> CC: pw_forum at pwscf.org
> From: giannozz at democritos.it
> Subject: Re: [Pw_forum] parallel computation too slow
> Date: Fri, 16 Mar 2012 21:48:15 +0100
> To: elie.moujaes at hotmail.co.uk
> 
> 
> On Mar 16, 2012, at 19:14 , Elie M wrote:
> 
> > I am running phonon calculations for a supercell of 60 atoms at the  
> > gamma point [...]
> > What could the possible causes of this slowness be? Is it something  
> > to do with the
> > nodes or with phonon calculations in general? Is there a way to check?
> 
> >
> 
> a phonon calculation for N atoms requires a CPU time of the order of  
> 3N the time of
> the correspoding  scf calculation. Does yours? if it does, there is  
> nothing that can be
> done.
> 
> P.
> ---
> Paolo Giannozzi, Dept of Chemistry&Physics&Environment,
> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
> 
> 
> 
> 
 		 	   		  
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