Collecting MPI Profile information might help narrow down the issue. You could use some of the tools mentioned here - http://www.open-mpi.org/faq/?category=perftools
--Nysal On Wed, Dec 1, 2010 at 11:59 PM, Price, Brian M (N-KCI) < brian.m.pr...@lmco.com> wrote: > 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 > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
