[OMPI users] Performance difference on OpenMPI, IntelMPI and ScaliMPI

2009-08-05 Thread Torgny Faxen
Hello, we are seeing a large difference in performance for some applications depending on what MPI is being used. Attached are performance numbers and oprofile output (first 30 lines) from one out of 14 nodes from one application run using OpenMPI, IntelMPI and Scali MPI respectively. Scali

Re: [OMPI users] Performance difference on OpenMPI, IntelMPI and ScaliMPI

2009-08-05 Thread Torgny Faxen
winner in terms of number of calls. /Torgny Pavel Shamis (Pasha) wrote: Do you know if the application use some collective operations ? Thanks Pasha Torgny Faxen wrote: Hello, we are seeing a large difference in performance for some applications depending on what MPI is being used. Attached

Re: [OMPI users] Performance difference on OpenMPI, IntelMPI and ScaliMPI

2009-08-05 Thread Torgny Faxen
remembered to compile your application with a -O3 flag - i.e., "mpicc -O3 ...". Remember, OMPI does not automatically add optimization flags to mpicc! Thanks Ralph On Wed, Aug 5, 2009 at 7:15 AM, Torgny Faxen <mailto:fa...@nsc.liu.se>> wrote: Pasha, no collectives are

Re: [OMPI users] Performance difference on OpenMPI, IntelMPI and ScaliMPI

2009-08-05 Thread Torgny Faxen
ll us to bind or else you lose a lot of performace. Set -mca opal_paffinity_alone 1 on your cmd line and it should make a significant difference. On Wed, Aug 5, 2009 at 8:10 AM, Torgny Faxen <mailto:fa...@nsc.liu.se>> wrote: Ralph, I am running through a locally provided wra

Re: [OMPI users] Performance difference on OpenMPI, IntelMPI and ScaliMPI

2009-08-06 Thread Torgny Faxen
Pasha, se attached file. I have traced how MPI_IPROBE is called and also managed to significantly reduce the number of calls to MPI_IPROBE. Unfortunately this only resulted in the program spending time in other routines. Basically the code runs through a number of timesteps and after each time