Issue No. 07 - July (2002 vol. 13)
<p>Editor's Note: This paper unfortunately contains some errors which led to the paper being reprinted in the November 2002 issue. Please see <i>IEEE Transactions on Parallel and Distributed Systems</i>, vol. 13, no. 11, November 2002, pp. 1166-1182 for the correct paper (<a href="http://computer.org/tpds/td2002/l1166.pdf">available without subscription</a>).</p> <p>Networks of workstations (NOWs) are becoming increasingly popular as a cost-effective alternative to parallel computers. These networks allow the customer to connect processors using irregular topologies, providing the wiring flexibility, scalability, and incremental expansion capability required in this environment. Some of these networks use source routing and wormhole switching. In particular, we are interested in Myrinet networks because it is a well-known commercial product and its behavior can be controlled by the software running in network interfaces (Myrinet Control Program, MCP). Usually, the Myrinet network uses up*/down* routing for computing the paths for every source-destination pair. In this paper, we propose the In-Transit Buffer (ITB) mechanism to improve network performance. We apply the ITB mechanism to NOWs with up*/down* source routing, like Myrinet, analyzing its behavior on both networks with regular and irregular topologies. The proposed scheme can be implemented on Myrinet networks by only modifying the MCP, without changing the network hardware. We evaluate by simulation several networks with different traffic patterns using timing parameters taken from the Myrinet network. Results show that the current routing schemes used in Myrinet networks can be strongly improved by applying the ITB mechanism. In general, our proposed scheme is able to double the network throughput on medium and large NOWs. Finally, we present a first implementation of the ITB mechanism on a Myrinet network.</p>
Networks of workstations, wormhole switching, minimal routing, source routing, performance evaluation.
J. Flich, P. López, M. Malumbres and J. Duato, "Boosting the Performance of Myrinet Networks," in IEEE Transactions on Parallel & Distributed Systems, vol. 13, no. , pp. 693-709, 2002.