Brent, > I get the following output in the pbs job error file > > mpiexec: Error: read_gm_startup_ports: accept gmpi_port#1 iter 0: Invalid > argument. > > What does this mean? and how do I fix it? Have you tested out your myrinet installation? What happens if you run: YOUR_PATH_TO_MYRINET/gm/binary/bin/gm_board_info Malcolm -- Malcolm Tobias 314.935.5289