Benchmarking the computation and communication performance of the CM-5

Thinking Machines' CM-5 machine is a distributed-memory, message-passing computer. In this paper we devise a performance benchmark for the base and vector units and the data communication networks of the CM-5 machine. We model the communication characteristics such as communication latency and bandwidths of point-to-point and global communication primitives. We show, on a simple Gaussian elimination code, that an accurate static performance estimation of parallel algorithms is possible by using those basic machine properties connected with computation, vectorization, communication, and synchronization. Furthermore, we describe the embedding of meshes or hypercubes on the CM-5 fat-tree topology and illustrate the performance results of their basic communication primitives. This work was supported in part by NSF under CCR-9110812 and by DARPA under contract # DABT63-91-C-0028. This work was also supported in part by a grant of HPC time from the DoD HPC Shared Resource Center, Army High-Performance Computer Center at University of Minnesota CM-5 machine. The contents do not necessarily re ect the position or the policy of the U.S.Government, and no o cial endorsement should be inferred.