Hi MPICH-developers, I’ve been trying to benchmark mpi software currently available on my univ. cluster with OSU micro benchmarks. I used this script to build and run the benchmark : https://github.com/s-sajid-ali/nu-quest-mpi/blob/master/curr_mpi_bench/submi... And here is a plot of the results I obtained : [image: curr_mpi.png] Could someone give me a clue as to why the behaviour of mpich bandwidth vs latency is so odd ? Why does the bandwidth increase first and then fall off at high message sizes? I’m also attaching the config.log for this particular mpich build which seems to indicate that MPICH was built with ch3 and nemesis:tcp. Does this mean that it didn’t pick up the infiniband libraries or that it is somehow using IPoIB? Is there a way to get this information ? Thanks in advance for the help! -- Sajid Ali | PhD Candidate Applied Physics Northwestern University s-sajid-ali.github.io