[mvapich-discuss] Question about NUMA support in mvapich2-1.2 (and later)

[Craig Tierney]

The mvapich2 documentation states:

Optimized for Bus-based SMP and NUMA-Based SMP systems.

But I cannot find any other reference to what exactly
mvapich2 does for NUMA-Based systems (like nehalem).  Simple
tests have shown that I cannot use numactl to explicitly
lay out MPI processes to improve performance for memory
bandwidth sensitive applications over just running
the application directly with mpirun.   But I would like
to understand what is being done by mvapich2.

Thanks,
Craig
-- 
Craig Tierney (craig.tierney at noaa.gov)