FAQ

1. MPICH/SCore on PM/Myrinet achieves less performance than MPICH/GM on Myrinet2000.

   MPICH/GM uses Zero-copy communication at default, MPICH/SCore does not use zero-copy communication at default. Please try to use mpi_zerocopy=on at scrun option, such as :
   

   % scrun -nodes=4x1,mpi_zerocopy=on a.out

2. MPICH/SCore on PM/Ethernet achieves less performance than MPICH/p4(LAM) on Ethernet.

   The default parameters defined in /opt/score/etc/pm-ethernet.conf are not optimized. Please optimize the parameters using maxnsend and backoff in pm-ethernet.conf .
   Or use mpi_eager option, such as:

   % scrun -nodes=4x1,mpi_eager=1000000 a.out

3. Scstest or rcstest fails on PM/Ethernet

   Please optimize the parameters using maxnsend and backoff in pm-ethernet.conf. Or use timeout option such as:

   % scstest -network ethernet -timeout 10
   % rcstest node00 ethernet -v -timeout 10

PC Cluster Consotium