Considering the relative importance of network performance and network features

Latency and bandwidth are usually considered to be the dominant factor in parallel application performance; however, recent studies have indicated that support for independent progress in MPI can also have a significant impact on application performance. This paper leverages the Cplant system at Sandia National Labs to compare a faster, vendor provided MPI library without independent progress to an internally developed MPI library that sacrifices some performance to provide independent progress. The results are surprising. Although some applications see significant negative impacts from the reduced network performance, others are more sensitive to the presence of independent progress.