Hi, I am not an HPL expert, but this might help. 1. rankfile mapper is avaliale only from Open MPI 1.3 version, if you are using Open MPI 1.2.8 try -mca mpi_paffinity_alone 1 2. if you are using Open MPI 1.3 you dont have to use mpi_leave_pinned 1 , since it's a default value
Lenny. On Thu, Jul 2, 2009 at 4:47 PM, Swamy Kandadai <sw...@us.ibm.com> wrote: > Jeff: > > I am running on a 2.66 GHz Nehalem node. On this node, the turbo mode and > hyperthreading are enabled. > When I run LINPACK with Intel MPI, I get 82.68 GFlops without much trouble. > > When I ran with OpenMPI (I have OpenMPI 1.2.8 but my colleague was using > 1.3.2). I was using the same MKL libraries both with OpenMPI and > Intel MPI. But with OpenMPI, the best I got so far is 80.22 GFlops and I > could never achieve close to what I am getting with Intel MPI. > Here are muy options with OpenMPI: > > mpirun -n 8 --machinefile hf --mca rmaps_rank_file_path rankfile --mca > coll_sm_info_num_procs 8 --mca btl self,sm -mca mpi_leave_pinned 1 > ./xhpl_ompi > > Here is my rankfile: > > at rankfile > rank 0=i02n05 slot=0 > rank 1=i02n05 slot=1 > rank 2=i02n05 slot=2 > rank 3=i02n05 slot=3 > rank 4=i02n05 slot=4 > rank 5=i02n05 slot=5 > rank 6=i02n05 slot=6 > rank 7=i02n05 slot=7 > > In this case the physical cores are 0-7 while the additional logical > processors with hyperthreading are 8-15. > With "top" command, I could see all the 8 tasks are running on 8 different > physical cores. I did not see > 2 MPI tasks running on the same physical core. Also, the program is not > paging as the problem size > fits in the meory. > > Do you have any ideas how I can improve the performance so that it matches > with Intel MPI performance? > Any suggestions will be greatly appreciated. > > Thanks > Swamy Kandadai > > > Dr. Swamy N. Kandadai > IBM Senior Certified Executive IT Specialist > STG WW Modular Systems Benchmark Center > STG WW HPC and BI CoC Benchmark Center > Phone:( 845) 433 -8429 (8-293) Fax:(845)432-9789 > sw...@us.ibm.com > http://w3.ibm.com/sales/systems/benchmarks > > > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
