A parallel system consists of a parallel algorithm and a parallel machine t
hat supports the implementation of the algorithm. The scalability of a para
llel system is a measure of its capability to increase speedup in Proportio
n to the number of processors, or its capability to keep a constant efficie
ncy as the number of processors increases. The present paper is devoted to
the investigation of the average-case scalability of parallel algorithms ex
ecuting oil multicomputers with symmetric static networks, including the co
mpletely connected network, ring, hypercube, and torus. In particular, we c
haracterize the communication overhead such that the expected efficiency ca
n be kept at certain constant level, and that the number of tasks grows at
the rate Theta(P log P). (C) 1999 Elsevier Science Ltd. All rights reserved
.