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A probabilistic relation between desirable and feasible, models of parallel computation

Published 1 January 1984Open access
Eli Upfal
Citations31
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TL;DR

It is proved that if a program required a program to take PRAM steps, the simulation algorithm executes it on the ULTRACOMPUTER within O(t)(log2n) steps with overwhelming probability.

Abstract

We present a powerful probabilistic technique for simulating strong models of synchronized parallel computation by weaker ones. The technique is demonstrated by an algorithm simulating an n processor PRAM, with an arbitrary large shared memory, by an n processor ULRTACOMPUTER (a set of n processors communicating through a bounded degree network, and sharing no common memory). We prove that if a program required t PRAM steps, our simulation algorithm executes it on the ULTRACOMPUTER within O(tlog2n) steps with overwhelming probability.

Keywords

Computer ScienceMathematics