User guide

A–Benchmark Programs
Benchmark 2: Measuring MPI Bandwidth Between Two Nodes
A-4 IB0054606-02 A
Benchmark 2: Measuring MPI Bandwidth
Between Two Nodes
The osu_bw benchmark measures the maximum rate that you can pump data
between two nodes. This benchmark also uses a ping-pong mechanism, similar to
the osu_latency code, except in this case, the originator of the messages
pumps a number of them (64 in the installed version) in succession using the
non-blocking MPI_I send function, while the receiving node consumes them as
quickly as it can using the non-blocking MPI_Irecv function, and then returns a
zero-length acknowledgement when all of the sent data has been received.
You can run this program by typing:
$ mpirun -H host1,host2 \
/usr/mpi/gcc/openmpi-1.4.3-qlc/tests/osu_benchmarks-3.1.1/osu
_bw