On Wed, 16 Aug 2006, Allan Menezes wrote:
Hi AnyOne, I have an 18 node cluster of heterogenous machines. I used fc5 smp kernel and ocsar 5.0 beta. I tried the following out on a machine with Open mpi 1.1 and 1.1.1b4 versions. The machine consists of a Dlink 1gigb/s DGE-530T etherent card 2.66GHz dual core Intel Cpu Pentium D 805 with Dual Cannel 1 gig DDR 3200 ram. I compiled the ATLAS libs (ver 3.7.13beta) for this machine and HPL (xhpl executable) and ran the following experiment twice: content of my "hosts" file1 for this machine for 1st experiment: a8.lightning.net slots=2 content of my "hosts" file2 for this machine for 2nd experiment: a8.lightning.netOn the single node I ran for HPL.dat N =6840 and NB=120 : 1024 MB of Ram N = sqrt(0.75* ((1024-32 video overhead)/2 )*1000000*1/8)=approx 6840; 512MB Ram per CPU otherwise the OS uses the hard drive for virtaul memory. This way it resides totally in Ram. I ran this command twice for the two different hosts files above in two experiments: # mpirun --prefix /opt/openmpi114 --hostsfile hosts -mca btl tcp, self -np 1 ./xhpl In both cases the performance remains the same around 4.040 GFlops I would expect since I am running slots =2 as two CPU's I would get a performance increase from expt 2 by 100 -50% But I see no difference.Can anybody tell me why this is so?
You are only launching 1 process in both cases. Try `mpirun -np 2 ...` to launch 2 processes, which will load each of your processors with an xhpl process. Please read the faq: http://www.open-mpi.org/faq/?category=running#simple-spmd-run It includes a lot of information about slots and how they should be set as well. Hugh
I have not tried mpich 2. Thank you, Regards, Allan Menezes _______________________________________________ users mailing list us...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/users
