Performance of Multicomputer Networks under Pin-out Constraints

Abstract When the performance of multiprocessor or multicomputer interconnection networks is modeled in the literature, it is usually assumed that communication links have a channel wide enough to accommodate the entire message so that switch-to-switch transfers can take place in one cycle. In practice, however, the channel width is constrained by real-world considerations. These constraints impact on the choice of network topology and mandate more sophisticated switching technologies. In this paper, we evaluate the performance of the family of multidimensional mesh topologies (which includes the hypercube) under the constant pin-out constraint. We assign a channel width to each system so that the product of the node degree and the channel width is constant and then analyze the stochastic performance of these systems using three schemes: message switching, virtual cut-through switching, and partial cut-through switching. Our analyses are more accurate than those appearing in the literature, and the results show that under the constant pin-out constraint, higher dimensionality is more important than wider channel width.