modify environment variable from MPICH

[Xiaobin_Q_]

Hi

I have some scripts for runing DART(a meteorology software) with intel compiler and intel mpi library. These scripts were used on cray and MPICH. The environment variable for MPICH setting are :

 26 setenv MPICH_VERSION_DISPLAY 1
 27 setenv MPICH_ENV_DISPLAY 1
 28 setenv MPICH_MPIIO_HINTS_DISPLAY 1
 29
 30 setenv MPICH_GNI_RDMA_THRESHOLD 2048
 31 setenv MPICH_GNI_DYNAMIC_CONN disabled
 32
 33 setenv MPICH_CPUMASK_DISPLAY 1
 34 setenv OMP_NUM_THREADS 1

On original machine 4000 CPU core were used.

On new linux machine with intel MPI, I commet out those variable. When I use 200 CPU core, it takes about 6000 seconds. But when I use 720 CPU core, it takes about 15000 seconds. If I use those  environment variable for intel MPI, will the performance improved? How to modify those  environment variable? Is there some introduction for setting both intel MPI and MPICH?

Thanks

[TimP]

If you have built with OpenMP enabled, you probably don't want to comment out OMP_NUM_THREADS, unless you intend to run 1 MPI rank per node (possibly with HT disabled).