In 2006, Microsoft® released its first high-performance computing (HPC) software offering, the Windows® Compute Cluster Server 2003 (WCCS 2003). Two years later, a new improved version was released and it was renamed as Windows High Performance Computing Server 2008 (WHPCS 2008) to increase its visibility in the HPC marketplace, which had been dominated by Linux® and UNIX® servers. Windows HPC is gradually gaining attention in the HPC community with a series of events. These include the November 2008 Top 500 list that contains five Windows systems. One of them is in the tenth position in the list.

In this IBM® Redpapers publication we present some Intel® MPI Benchmarks (IMB) on an InfiniBand® 4x SDR cluster of IBM System x® 3550 systems running WCCS 2003. For comparison purposes, we have also performed Linux runs on a similar system: A System x3650 with InfiniBand 4x SDR interconnects. The System x3650 has the same processor and memory configuration as the System x3550.