On single parameter characterization of parallelism

Issues pertinent to performance analysis of massively parallel systems are discussed. Attention is focused on the average parallelism of a software structure, which has been proposed as a single-parameter characterization of parallel software. It is argued that single-parameter characterization of parallel software or of parallel hardware rarely provides insight into the complex interactions among the software and hardware components of a parallel system. In particular, bounds for the speedup based on simple models of parallelism are violated when a model ignores the effects of communication delays.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>