The focus of this paper is to evaluate the use of two different network topologies for Ethernet networks in small Common

Off The Shelf (COTS) clusters. The fully meshed network topology was evaluated and its impact on latency and

bandwidth was measured and compared to the more traditional switched network topology. This was done at MPI level

by measuring the point-to-point round trip latency (ping-pong) and all-to-alla bandwidth for different sized messages.

The results from the experiments are presented and the overall the benefits and drawbacks of the both approaches are

discussed.