[gmx-users] MPI gromacs usage

[Milan Melichercik]

Dňa Ut 18. Júl 2006 16:20 Diane Fournier napísal:
> Hi gromacs users
>
> I've already used gromacs single-processor version and I want to use the
> parallel version of gromacs on a SGI Altix 2700 with 32 processors. I'm
> wondering how to proceed, because this does not seem to be explained
> properly anywhere. Do I have to give special instructions in grompp to
> split the simulation on several processors, or can I use the same .tpr file
> I'm using with the single-processor version of mdrun ?

At first, you must have compiled GROMACS with MPI support [ --enable-mpi 
directive by ./configure command]. After that, there are small differences - 
grompp must split task for 32 processors (in your case) [ -np 32 directive] 
and you have to run mdrun through mpirun/mpiexec/... command (this depends on 
MPI library you use). And also the mdrun should know you have 32 simultaneous 
processes [ -np 32 directive]. So you can't use the same .tpr file.
I hope, this will help a little.