The ABINIT Users Mailing List ( CLOSED )

[Nicola Marzari <marzari@mit.edu>]

Apologies - I never mentioned parallelization over k-points.
That is more or less trivially parallel, and should scale
linearly with number of processors. Note that the memory that
each process needs to have allocated remains constant - so
k-point parallelization doesn't really help to go towards larger
systems that do not fit on one motherboard to begin with.

                                nicola


Marcel Mohr wrote:
> without parallelization over k-points, it is getting worser: timer: 
> Routine,Calls,Time,% = IterSCF        1    1988.396  97.37
> elaps: Routine,Calls,Wall,% = IterSCF        1     545.233  97.17
>
> On Tue, 28 Aug 2007, Marcel Mohr wrote:
>
> > Another option:
> > We use dual xeons on a dual motherboard.
> > Here is an example output from the LCAO DFT code SIESTA (I have no 
> > parallel abinit output.)
> > I used parallelization over 8  k-points.
> >
> > timer: Routine,Calls,Time,% = IterSCF        1    2377.865  97.82
> > elaps: Routine,Calls,Wall,% = IterSCF        1     605.648  97.42
> >
> > In the 1. line is the cpu time, below is the elapsed time.
> > Here the time almost scales linearly with number of processors. (3.92 
> > instead of 4)
> >
> > Cheers Marcel
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Prof Nicola Marzari   Department of Materials Science and Engineering
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