[Beowulf] Compare and contrast MPI implementations

[David Mathog]

There are at least 4 free MPI implementations:

name     version   MPI standard   where
mpich    1.2.7p1   1.2         http://www-unix.mcs.anl.gov/mpi/mpich/
mpich2   1.0.3     2           http://www-unix.mcs.anl.gov/mpi/mpich2/
lam/mpi  7.1.1     1.2,some 2  http://www.lam-mpi.org/ 
open-mpi 1.0       2           http://www.open-mpi.org/

What advantages and disadvantages do each of these have?  I looked
around for a review article or something of that sort but didn't find
anything.

The cluster in question has only 100baseT, so support for
Myrinet and other faster interconnects doesn't matter for us. It
currently has an older version of mpich 1 installed, but that sees no
use since the commonly used software is all PVM.  I want to run gromacs
now, and they suggest using lam/mpi, but don't say *why* they
suggest it.

Are the MPI 2 standards fully backwards compatible with code written
to the MPI 1.2 standard?

Thanks,

David Mathog
mathog at caltech.edu
Manager, Sequence Analysis Facility, Biology Division, Caltech