Inside the Message Passing Interface

Chapter 6 Tuning

In this book, the term MPI tuning denotes MPI performance optimization done by proper selection of the already existing code paths and their parameters rather than by source code changes. Tuning attempts to make the product achieve the best possible performance on a particular system—out in the field, rather than in your own test lab.

Tuning seeks to improve latency or bandwidth of a certain communication pattern like ping-pong, of a set of collective operations, of a target application performance expressed in wall clock time or an application-specific rating, or of any sensible mixture thereof. However, tuning is only the last and rather expensive polish applied to an otherwise finished MPI library. If you have not carefully ...