Hello, There is possibly a run away process running on RedHawk taking-up one core on the head node: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 20681 xus2 20 0 9112 2728 1132 R 94.2 0.0 8819:11 nmrdraw.exe thanks with regards D. M. Rao