Jed Brown wrote:
> Are you saying the output of mpicc/mpif90 -show has the same
> optimization flags? MPICH2 usually puts it's own optimization flags
> into the wrappers.
Jed, thank you for your reply. Yes, mpif90 shows (other than differing
libraries) identical flags.
Ralph Castain wrote:
> Did you set -mca mpi_paffinity_alone 1? This will bind the processes
> to cores and (usually) significantly improve performance.
Ralph, thank you for the suggestion. I had focussed on RDMA, and this
made a significant difference. I have only had time to re-run an
ensemble of one configuration (rather than the suite I had been
running) and it improved the OpenMPI performance by 19.5%. So, it
would appear this was the primary cause.
I will read through the documentation to find how to make this the
Thank you for your assistance! I look forward to the 1.3.4 improvements.