Performance Considerations

The pipe size should be at most half as big as the connection pool

2 * MPI_RSM_PIPESIZE <= MPI_RSM_CPOOLSIZE

Otherwise, pipelined transfers will proceed slowly. The library adjusts MPI_RSM_PIPESIZE appropriately.

Reducing striping has no performance advantage, but varying MPI_RSM_MAXSTRIPE can give you insight into the relationship between application performance depends and internode bandwidth.

For pipelined messages, a sender must synchronize with its receiver to ensure that remote writes to buffers have completed before postboxes are written. Long pipelined messages can absorb this synchronization cost, but performance for short pipelined messages will suffer. In some cases, raising MPI_RSM_SHORTMSGSIZE can mitigate this effect.