Improving Routing Performance in Myrinet Networks

Networks of workstations (NOWs) are becoming incre-asingly popular as a cost-effective alternative to parallel computers. Typically, these networks connect processors using irregular topologies, providing the wiring flexibility, scalability, and incremental expansion capability required in this environment. In some of these networks [1], packets are delivered using source routing. Due to the irregular topology, the rou-ting scheme is often non-minimal. In this paper we analyze the routing scheme used in Myrinet networks in order to im-prove its performance. We propose new routing algorithms that balance the utilization of the available routes and al-ways use minimal paths. We show through simulation that the current routing schemes used in Myrinet networks can be improved by mo-difying only the routing software without increasing the software overhead significantly. The overall throughput can be doubled without modifying the network hardware