Structured Communication in Cut-through Routed Torus Networks

This paper is a study of one-to-all and all-to-all data movement patterns on cycles and multi-dimensional toroidal meshes that use cut-through (e.g., circuit-switched, wormhole) routing with virtual channels. We present new cut-through algorithms for broadcasting, scattering, gossiping, and multi-scattering on cycles and multi-dimensional torus networks. Our algorithms use virtual channels to improve performance by controlled use of channel connicts. We compare our algorithms to the best known store-and-forward algorithms, cut-through algorithms, and lower bounds. In most cases, we conclude that cut-through routing is best when messages are \short" and store-and-forward routing is best for long messages. Some of our new algorithms outperform all known algorithms for all message lengths.