% mpicc -o pingpong pingpong.c % mpirun -np 2 pingpong Kind n time (sec) Rate (MB/sec) Send/Recv 1 0.003574 0.002238 Send/Recv 2 0.003592 0.004455 Send/Recv 4 0.003603 0.008882 Send/Recv 8 0.003621 0.017675 Send/Recv 16 0.003678 0.034803 Send/Recv 32 0.003709 0.069020 Send/Recv 64 0.003735 0.137084 Send/Recv 128 0.004264 0.240178 Send/Recv 256 0.005268 0.388799 Send/Recv 512 0.007890 0.519171 Send/Recv 1024 0.011941 0.686011 Send/Recv 2048 0.021438 0.764250 Send/Recv 4096 0.038588 0.849165 Send/Recv 8192 0.077029 0.850802 Send/Recv 16384 0.146270 0.896096 Send/Recv 32768 0.287323 0.912367 Send/Recv 65536 0.575686 0.910719 Send/Recv 131072 1.193515 0.878562 Send/Recv 262144 2.309940 0.907882 Send/Recv 524288 4.651385 0.901732 p0_26008: p4_error: interrupt SIGINT: 2 p0_26008: p4_error: interrupt SIGINT: 2 bm_list_26009: p4_error: interrupt SIGINT: 2