MPI Communication in SMP Clusters

The recent years have seen a considerable increase in the number of cluster systems. These systems provide a very good performance-cost ratio. However, in order to meet the requirements for ever-increasing computing power of present day applications, several SMP cluster systems have emerged. By deploying two or more processors per workstation can increase the performance of a cluster significantly. The introduction of SMP workstations to a cluster adds a new dimension to the communication between processors. The purpose of this paper is to discuss the impact of SMP workstations in a cluster with respect to the communication. The communication mechanisms are studied and their performances are evaluated. In addition, performance results from a special communication library called MPIT, which is optimized to handle communication operations in SMP clusters, are compared to the traditional communication schemes available for the SMP cluster environments. Key-Words: SMP, Clusters, Communication, MPI, Networks of workstations, message passing, performance evaluation