Dr. Swamy N. Kandadai Certified Sr. Consulting IT Specialist HPC Benchmark Center System & Technology Group, Poughkeepsie, NY Phone:( 845) 433 -8429 (8-293) Fax:(845)432-9789 sw...@us.ibm.com http://w3.ibm.com/sales/systems/benchmarks
----- Forwarded by Swamy Kandadai/Poughkeepsie/IBM on 06/23/2006 10:21 PM ----- Swamy Kandadai/Poughkee psie/IBM To us...@open-mpi.org 06/23/2006 09:52 cc PM Subject OpenMPI version 1.1 Hi: I am trying to run OpenMPI on a couple of nodes. These nodes have several interfaces: eth0 (which is a GigE), eth1 (which is a GigE with Jumbo frames enabled), IpoIB, myr0 in addition to loopback (l0). I want to use exclusively eth1 and I am running with this option: mpirun --mca btl_tcp_if_include eth1 -machinefile hf -np 2 IMB-MPI1 where IMB-MPI1 is the Intel message passing benchmark. Different times, it has different behaviors: I ran on one set of nodes and I got a typical GigE behavior (around 100 MB/s). On a different pairs of nodes it is giving me the BW consistent with IpoIB (around 700 MB/s). Can u help me what I am doing wrong? How can I force it to use eth1 on all nodes? I just built OpenMPI with the following option: ./configure --prefix=$BINDIR --disable-io-romio Thanks Swamy Dr. Swamy N. Kandadai Certified Sr. Consulting IT Specialist HPC Benchmark Center System & Technology Group, Poughkeepsie, NY Phone:( 845) 433 -8429 (8-293) Fax:(845)432-9789 sw...@us.ibm.com http://w3.ibm.com/sales/systems/benchmarks