Abstract

In order to develop efficient applications for large scale multiprocessors, the communication patterns of the target architecture should be well understood. By understanding these communication patterns, a faster running application can be developed. Some applications require the smallest latency possible, whereas others might benefit from higher throughput. The Cray T3D is a multiprocessor that has a high speed 3D torus interconnect, and special communications hardware. By utilizing this hardware properly, a program has the potential to minimize its communications overhead. This study investigates three different libraries that provide communication on the T3D: PVM, MPI, and SMA. Both PVM and MPI are portable, whereas SMA is native. The latency, bandwidth, and collective communication costs of the communication primitives implemented in these libraries are characterized and compared. These results are also briefly contrasted with the results of related studies on the IBM SP2 and the C...

Citations