A look at application performance sensitivity to the bandwidth and latency of InfiniBand networks

This work explores the expected performance of three applications on a high performance computing cluster interconnected using InfiniBand. In particular, the expected performance across a range of configurations is analyzed notably InfiniBand 4times, 8times and 12times representing link-speeds of 10 Gb/s, 20 Gb/s, and 30 Gb/s respectively as well as near-neighbor MPI message latencies of 4mus and 1.5mus. In addition we also consider the impact of node size, from one to eight processors that share a single network connection. The performance analysis is based on the use of detailed performance models of the three applications developed at Los Alamos. The results of the analysis show that the application performance can range by as much as 60% from best to worst. The relative importance of bandwidth, latency and node size differs between the applications