Analysis of the Numerical Effects of Parallelism on a Parallel Genetic Algorithm William E. Hart Massively Parallel Computing Research Laboratory Sandia National Laboratories Albuquerque, NM 87185-1110 Scott Baden, Richard K. Belew, Scott Kohn Computer Science end Engineering Department University of California - San Diego La Jolla, CA 92093 In Proceedings of the 10th International Parallel Processing Symposium, 1996. pp. 606-612. Abstract: This paper examines the effects of relaxed synchronization on both the numerical and parallel efficiency of parallel genetic algorithms (GAs). We describe a coarse-grain geographically structured parallel genetic algorithm. Our experiments provide preliminary evidence that asynchronous versions of these algorithms have a lower run time than synchronous GAs. Our analysis shows that this improvement is due to (1) decreased synchronization costs and (2) high numerical efficiency (e.g. fewer function evaluations) for the asynchronous GAs. This analysis includes a critique of the utility of traditional parallel performance measures for parallel GAs.