Perfonnance evaluation of gigabit ethernet and SCI in a linux cluster

Clusters are now one of the most preferred architectures for building high performance computing systems. The emergence of high speed commodity microprocessors, network technologies and Open Source operating systems have propelled the cluster concept to an unparalleled high. Even though most clusters nowadays use LAN technologies such as Fast and Gigabit Ethernet as the interconnect, there is a growing breed of new interconnection technologies called SAN (System Area Network) specifically designed for HPC. These new technologies boast characteristics such as high bandwidth, low latency for communications and scalability to large number of nodes that are so essential for most HPC applications. In this paper, we compare the performance of Gigabit Ethernet (LAN), and Scalable Coherent Interface (SAN) on a 128-processor Linux cluster. We present the raw bandwidth and latency figures of the two networks and then discuss the performance of several benchmark programs.