On the performance merits of bypass channels in hypermeshes and k-ary n-cubes

Low-dimensional k-ary n-cubes have been popular in recent multicomputers. T hese networks, however, suffer from high switching delays due to their high message distance. To overcome this problem, Daily has proposed a variation , called express k-ary rt-cubes, with express channels that allow non-local messages to partially bypass clusters of nodes within a dimension. K-ary n -cubes are graph topologies where a channel connects exactly two nodes. Thi s study argues that hypergraph topologies, where a channel connects any num ber of nodes, thus providing total bypasses within a dimension, represent p otential candidates for future high performance networks. It presents a com parative analysis, of a regular hypergraph, referred to as the distributed crossbar switch hypermesh (DCSH), and the express k-ary n-cube. The analysi s considers channel bandwidth constraints which apply in different implemen tation technologies. The results conclude that the DCSH's total bypass stra tegy yields superior performance characteristics to the partial bypassing o f its express cube counterpart.