Note that since you are setting OMPI_MCA_pml to cm, OMPI_MCA_btl will have no effect. You may try setting OMPI_MCA_pml=ob1, and trying your measurements again, but we generally get better performance with the cm pml than then ob1 pml.
Tim On Wednesday 06 June 2007 12:54:26 pm George Bosilca wrote: > Which one is the latency with Open MPI ? Which version of Open MPI ? > > You might want to use OMPI_MCA_btl=mx,self to see if it makes any > difference. > > Thanks, > george. > > On Jun 6, 2007, at 12:26 PM, Maestas, Christopher Daniel wrote: > > With 2 nodes using 1.1.7 with the patch we measured (using mpich-mx > > 1.2.7..4): > > 3.07us > > > > With mx 1.2.1-rc18 we measure: > > 3.69 us > > And with mpich-mx 1.2.7..4 we see: > > 3.20us > > > > Our Open MPI settings: > > --- > > # env | grep OMPI > > OMPI_MCA_pml=cm > > OMPI_MCA_mpi_keep_hostnames=1 > > OMPI_MCA_oob_tcp_include=eth0 > > OMPI_MCA_btl=mx,sm,self > > > > Does anyone know why the latency would be slightly higher using > > Open MPI > > versus MPICH-MX? > > > > Thanks, > > -cdm > > > > > > _______________________________________________ > > users mailing list > > us...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/users
