I've been comparing 1.5.4 and 1.5.5rc3 with the same parameters that's why I didn't use --bind-to-core. I checked and the usage of --bind-to-core improved the result comparing to 1.5.4: #repetitions t_min[usec] t_max[usec] t_avg[usec] 1000 84.96 85.08 85.02
So I guess with 1.5.5 the processes move from core to core within node even though I use all cores, right? Then why 1.5.4 behaves differently? I need --bind-to-core in some cases and that's why I need 1.5.5rc3 instead of more stable 1.5.4. I know that I can use numactl explicitly but --bind-to-core is more convinient :) 2012/3/23 Ralph Castain <r...@open-mpi.org> > I don't see where you told OMPI to --bind-to-core. We don't automatically > bind, so you have to explicitly tell us to do so. > > On Mar 23, 2012, at 6:20 AM, Pavel Mezentsev wrote: > > > Hello > > > > I'm doing some testing with IMB and dicovered a strange thing: > > > > Since I have a system with new AMD opteron 6276 processors I'm using > 1.5.5rc3 since it supports binding to cores. > > > > But when I run the barrier test form intel mpi benchmarks, the best I > get is: > > #repetitions t_min[usec] t_max[usec] t_avg[usec] > > 598 15159.56 15211.05 15184.70 > > (/opt/openmpi-1.5.5rc3/intel12/bin/mpirun -x OMP_NUM_THREADS=1 > -hostfile hosts_all2all_2 -npernode 32 --mca btl openib,sm,self -mca > coll_tuned_use_dynamic_rules 1 -mca coll_tuned_barrier_algorithm 1 -np 256 > openmpi-1.5.5rc3/intel12/IMB-MPI1 -off_cache 16,64 -msglog 1:16 -npmin 256 > barrier) > > > > And with openmpi 1.5.4 the result is much better: > > #repetitions t_min[usec] t_max[usec] t_avg[usec] > > 1000 113.23 113.33 113.28 > > > > (/opt/openmpi-1.5.4/intel12/bin/mpirun -x OMP_NUM_THREADS=1 -hostfile > hosts_all2all_2 -npernode 32 --mca btl openib,sm,self -mca > coll_tuned_use_dynamic_rules 1 -mca coll_tuned_barrier_algorithm 3 -np 256 > openmpi-1.5.4/intel12/IMB-MPI1 -off_cache 16,64 -msglog 1:16 -npmin 256 > barrier) > > > > and still I couldn't come close to the result I got with mvapich: > > #repetitions t_min[usec] t_max[usec] t_avg[usec] > > 1000 17.51 17.53 17.53 > > > > (/opt/mvapich2-1.8/intel12/bin/mpiexec.hydra -env OMP_NUM_THREADS 1 > -hostfile hosts_all2all_2 -np 256 mvapich2-1.8/intel12/IMB-MPI1 -mem 2 > -off_cache 16,64 -msglog 1:16 -npmin 256 barrier) > > > > I dunno if this is a bug or me doing something not the way I should. So > is there a way to improve my results? > > > > Best regards, > > Pavel Mezentsev > > > > > > _______________________________________________ > > devel mailing list > > de...@open-mpi.org > > http://www.open-mpi.org/mailman/listinfo.cgi/devel > > > _______________________________________________ > devel mailing list > de...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/devel >