Does your application do a lot of printing to stdout/stderr?
On Jan 11, 2010, at 8:00 AM, Mathieu Gontier wrote:
> Hi all
>
> I want to migrate my CFD application from MPICH-1.2.4 (ch_p4 device) to OpenMPI-1.4. Hence, I compared the two libraries compiled with my application and I noted OpenMPI is less efficient thant MPICH on ethernet (170min with MPICH against 200min with OpenMPI). So, I wonder if someone has more information/explanation.
>
> Here the configure options of OpenMPI:
>
> export FC=gfortran
> export F77=$FC
> export CC=gcc
> export PREFIX=/usr/local/bin/openmpi-1.4
> ./configure --prefix=$PREFIX --enable-cxx-exceptions --enable-mpi-f77 --enable-mpi-f90 --enable-mpi-cxx --enable-mpi-cxx-seek --enable-dist --enable-mpi-profile --enable-binaries --enable-cxx-exceptions --enable-mpi-threads --enable-memchecker --with-pic --with-threads --with-valgrind --with-libnuma --with-openib
>
> Despite my OpenMPI compilation supports OpenIB, I did not specified any mca/btl options because the machine does not have access to a Infiniband interconnect. So, I guess tcp, sm and self are used (or at least something close).
>
> Thank you for your help.
> Mathieu.
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