For the app I am using, ORCA (a Quantum Chemistry program), when it was compiled using openMPI 1.2.8 and run under 1.2.8 with the following in the openmpi-mca-params.conf file:
btl=self,openib the app ran fine with no traffic over my Ethernet network and all traffic over my Infiniband network. However, now that ORCA has been recompiled with openMPI v1.3.2 and run under 1.3.2 (using the same openmpi-mca-params.conf file), the performance has been reduced by 50% and all the MPI traffic is going over the Ethernet network. As a matter of fact, the openMPI v1.3.2 performance now looks exactly like the performance I get if I use MPICH 1.2.7. Anyone have any ideas: 1) How could this have happened? 2) How can I fix it? a 50% reduction in performance is just not acceptable. Ideas/ suggestions would be appreciated. Jim
