Architectural and Performance Evaluation of GigaNet and Myrinet Interconnects on Clusters of Small-Scale SMP Servers

GigaNet and Myrinet are two of the leading interconnects for clusters of commodity computer systems. Both provide memory-protected user-level network interface access, and deliver low-latency and high-bandwidth communication to applications. GigaNet is a connection-oriented interconnect based on a hardware implementation of Virtual Interface (VI) Architecture and Asynchronous Transfer Mode (ATM) technologies. Myrinet is a connection-less interconnect which leverages packet switching technologies from experimental Massively Parallel Processors (MPP) networks. This paper investigates their architectural differences and evaluates their performance on two commodity clusters based on two generations of Symmetric Multiple Processors (SMP) servers. The performance measurements reported here suggest that the implementation of Message Passing Interface (MPI) significantly affects the cluster performance. Although MPICH-GM over Myrinet demonstrates lower latency with small messages, the polling-driven implementation of MPICH-GM often leads to tight synchronization between communication processes and higher CPU overhead.