Comparative Performance Analysis of k-Ary n-Cube Topologies with Multiple Virtual Channels and Finite Size Buffers

Comparative Performance Analysis of k-Ary n-Cube Topologies with Multiple Virtual Channels and Finite Size Buffers N. Alzeidi, M. Ould-Khaoua, L. M. Mackenzie Computing Science Department, University of Glasgow, UK {zeidi, mohamed, lewis}@dcs.gla.ac.uk Abstract Comparative performance studies of k-ary n-cubes under different design constraints and operating conditions have been widely reported in the literature. When deterministic routing is used, researchers have shown that under bisection width constraint the torus outperforms the hypercubes while the converse is true when the network is subject to pin-out constraint. However, when adaptive routing is used, it has been shown that the network exhibiting the best performance depends on the network size and the imposed implementation constraints. However, all of these studies have assumed single flit buffers. Deploying finite size buffers, however, may add extra complexity to the router design and hence will influence the cost and the performance of the network. In this research we re-examine the relative performance merits of different k-ary n-cube topologies combining wormhole switching, adaptive routing, multiple virtual channels and finite size buffers. New analytical models that were able to capture the effects of finite buffers and virtual channels along with a cost-performance model have been used in the analyses. The results reveal new insights demonstrating the sensitivity of these studies to the level of detail and realism incorporated in the used analytical models.