Analysis of buffer design for adaptive routing in direct networks

The performance of a massively parallel computing system is often limited by the speed of its interconnection network. One strategy that has been proposed for improving network efficiency is the use of adaptive routing, in which network state information can be used an determining message paths. The design of an adaptive routing system involves several parameters, and in order to build high speed scalable computing systems, it is important to understand the costs and performance benefits of these parameters. We investigate the effect of buffer design on communication latency. Four message storage models and their related route selection algorithms are analyzed. A comparison of their performance is presented, and the features of buffer design which are found to significantly impact network efficiency are discussed.