[Beowulf] Network benchmark - MPI

[Jonathan Michael Nowacki]

Just wondering, if their is a benchmark or program that I can use to test
the maximum bandwidth of a cluster from node to node, or all nodes
communicating to the master node.  I'm thinking any kind of bandwidth test
will do, but the purpose is to see how much traffic a 40 node cluster can
take when running MrBayes (a MPI program).

thanks in advance,
   Jon