Performance Evaluation of a Parallel I/O Subsystem for Hypercube Multicomputers

Though input/output (I/O) from mass storage continues to be a bottleneck in current generation distributed-memory multicomputers, few studies have been conducted on the system-level impact of an independent I/O network and distributed file system for such machines. This paper quantifies the improvement in performance obtained in a hypercube multicomputer by providing a separate network that serves multiple I/O nodes operating under a distributed file system. First, the concept of balanced architectures is used to show that for a general purpose multicomputer with N processing elements, the I/O subsystem should scale as N log N . Analytical and simulation studies are performed on a hypercube architecture that is augmented by an independent I/O network that achieves this scale factor. For wormhole routing, a significant improvement in latency can be obtained for both small inter-processor messages and much larger I/O transactions, provided the bandwidth of a channel in the I/O networ..