OpenMPI version: 1.4.3
Platform: IBM P5, 32 processors, 256 GB memory, Symmetric Multi-Threading (SMT) 
enabled
Application: starts up 48 processes and does MPI using MPI_Barrier, MPI_Get, 
MPI_Put (lots of transfers, large amounts of data)
Issue:  When implemented using Open MPI vs. IBM's MPI ('poe' from HPC Toolkit), 
the application runs 3-5 times slower.
I suspect that IBM's MPI implementation must take advantage of some knowledge 
that it has about data transfers that Open MPI is not taking advantage of.
Any suggestions?
Thanks,
Brian Price

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