The Use of the MPI Communication Library in the NAS Parallel Benchmarks

The statistical analysis of traces taken from the NAS Parallel Benchmarks can tell one much about the type of network tra c that can be expected from scienti c applications run on distributed memory parallel computers. For instance, such applications utilize a relatively few number of communication library functions, the length of their messages is widely varying, they use many more short messages than long ones, and within a single application the messages tend to follow relatively simple patterns. Hardware and software designers can use information such as this to optimize their systems for the highest possible performance. This paper presents speci c data on how these generally known characteristics about distributed memory applications are exhibited in the NAS Parallel Benchmarks.