two things: 1. Too many mpi processes on one node leading to processes pre-empting each other 2. Contention in your network.
On Wed, Feb 29, 2012 at 8:01 AM, Pinero, Pedro_jose < pedro_jose.pin...@atmel.com> wrote: > Hi,**** > > ** ** > > I am using OMPI v.1.5.5 to communicate 200 Processes in a 2-Computers > cluster connected though Ethernet, obtaining a very poor performance. I > have measured each operation time and I haver realised that the MPI_Gather > operation takes about 1 second in each synchronization (only an integer is > send in each case). Is this time range normal or I have a synchronization > problem? Is there any way to improve this performance?**** > > ** ** > > Thank you for your help in advance**** > > ** ** > > Pedro**** > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
