openmpi versus mpich2

[Eric A. Borisch]

On Sun, Aug 7, 2011 at 11:07 PM, Rodolfo Aramayo <raramayo at gmail.com> wrote:
> Basic question:
> Can these two ports be installed side by side:
> openmpi and mpich2
> and
> which one is better for what purposes or are they equivalent in
> function and performance?
>
> --Thanks
>
> --R

Provided mpich2 is not installed with +default (conflict is noted in
variant description) the two should happily coexist. (I say *should*
as I haven't tried it recently.)

As to which is better... it depends. They both implement the MPI2
standard, so they both solve the same problem, in many respects. IMHO,
OpenMPI is designed to provide lots of run-time adjustments, while
MPICH2 tends to be more set at (mpich2) compile time. I'm sure you can
find plenty of opinions online with a Google search.

 I prefer mpich2 as I use mvapich2 on other (linux-based Infiniband
cluster) systems, which is itself based on mpich2.

Good luck,
 Eric
-- 
Eric A. Borisch (mpich2 port maintainer)