Effective Communication and File-I/O Bandwidth Benchmarks

Abstract

We describe the design and MPI implementation of two benchmarks created to characterize the balanced system performance of high-performance clusters and supercomputers: b eff, the communication- specific benchmark examines the parallel message passing performance of a system, and b eff io, which characterizes the effective I/O bandwidth. Both benchmarks have two goals: a) to get a detailed insight into the performance strengths and weaknesses of different parallel communication and I/O patterns, and based on this, b) to obtain a single bandwidth number that characterizes the average performance of the system namely communication and I/O bandwidth. Both benchmarks use a time-driven approach and loop over a variety of communication and access patterns to characterize a system in an automated fashion. Results of the two benchmarks are given for several systems including IBM SPs, Cray T3E, NEC SX-5, and Hitachi SR 8000. After a redesign of b eff io, I/O bandwidth results for several compute partition sizes are achieved in an appropriate time for rapid benchmarking.