Re: [ESPResSo] running espresso in parallel

[Axel Arnold]

On Sa, September 27, 2008 11:09, siamak jadidi wrote:
>                                                        ALLAH
> dear all
> I want to run Espresso in parallel on 2 machines(each one 8 cpu's )
> so first I make a host file and then
> lamboot -v host
>
> mpirun -np 16   ./lj_liquid.tcl
> but in this case it runs 8 times instead of running in parallel
> and if
> lamboot -v host
>   ./lj_liquid.tcl
> it is only runs on 2 cores of one machine.
> what can I do?

All the provided scripts such as lj_liquid.tcl use the Espresso-script
from the object-directory, which includes the mpi call. Per default, a
script runs on 2 processors, as you have realized. You have two
possibilities:

- the scripts accept a parameter which is the number of processors, so
"./lj_liquid.tcl 16" will run on 16 processors.
- you can not use this magic, by running Espresso_bin as interpreter:
"mpirun -np 16 obj-????/Espresso_bin lj_liquid.tcl", where obj-??? denotes
the directory where Espresso was compiled to. It always starts with obj-,
and if you didn't compile on different architectures, yet, there should be
just one in your Espresso source directory.

Many regards,
Axel