[gmx-developers] compiling parallel on amd64

[David]

On Thu, 2005-11-17 at 17:12 +0100, Florian Haberl wrote:
> Hi,
> 
> On Thursday 17 November 2005 12:30, David van der Spoel wrote:
> > On Thu, 2005-11-17 at 11:09 +0000, Julie Harold wrote:
> > > Hi,
> > >
> > > can anyone tell me the right flags for compiling parallel gromacs on
> > > amd64.  We have pgi compilers, fftw-2.1.5, and need it to be 64 bit.
> >
> > Do yourself a favor and use gcc. Less hassle and faster code. The one
> > thing you don't mention is which gromacs version. For 3.3 you want to
> > use fftw 3.0.1
> 
> David you mentioned to use fftw 3.0.1 with 3.3, is there now a buildin wrapper 
> for enabling parallel mpi runs with fftw, cause fftw.org say only fftw 2.1.* 
> will run with mpi?
Yes.

> And as always how much speed improvment is this (2.1* vs 3.*)?
Depending on your hardware, roughly:
P4: 0-5%
Opteron: 5-15%
Itanium: 100%


> 
> 
> >
> > > thanks,
> > >
> > > Julie
> 
> Greetings,
> 
> Florian
> 
-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,          75124 Uppsala, Sweden
phone:  46 18 471 4205          fax: 46 18 511 755
spoel at xray.bmc.uu.se    spoel at gromacs.org   http://xray.bmc.uu.se/~spoel
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