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
30 setenv MPICH_GNI_RDMA_THRESHOLD 2048
31 setenv MPICH_GNI_DYNAMIC_CONN disabled
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?