Mapping onto three classes of parallel machines: a case study using the cyclic reduction algorithm

Mapping cyclic reduction, a known approach for the parallel solution of tridiagonal systems of equations, onto the MasPar MP-1, nCUBE 2, and PASM parallel machines is discussed. Each of these represents a different mode of parallelism. Issues addressed are SIMD/MIMD trade-offs, the effect on execution time of increasing the number of processors used, the impact of the inter-processor communications network on performance, the importance of predicting algorithm performance as a function of the mapping used, and the advantages of a partitionable system. Analytical results are validated by experimentation on all three machines.<>