I guess that depends on what resources you request and how the cluster is setup! PETSc devs recommend binding MPI processes to sockets too, so I presume that applies to clusters as well.
I think vader backend will be useful regardless of whether your machine is in a cluster or not. My understanding is that OpenMPI knows about the hierarchy of interconnects and will use the fastest one available. So you can use the btl ordering self,vader,openib on a cluster and local processes will use the vader mechanism to transfer messages whilst remote processes will still use infiniband. The standard hierarchy for btl is something like self,sm,openib. vader with a cma backend will always beat sm, so if you can you should use it. Next year we will get another machine so we will have two large NUMA machines with infiniband. Then I can give some more definite answers to your questions. ----- Dr. Jack S. Hale University of Luxembourg _______________________________________________ fenics mailing list [email protected] http://fenicsproject.org/mailman/listinfo/fenics
