On the Relation between Solution Quality and Computing Times of Intelligent Algorithms − A Comparative Study for Standard Cell Placement in VLSI Design

Many heuristic methods for NP hard optimization problems were developed in the past. Recently several new approaches based on analogies to processes of nature have been proposed. Considering the variety of methods available, a crucial question is which one to choose in practice. The behavior of any method depends strongly on parameters. Furthermore, time constraints often play an important role and the stability of a method may be a relevant factor to consider. In this paper, some assistance for the decision which method to select will be given. The methods under investigation are: simulated annealing, tabu search, threshold accepting, genetic algorithms, and a hybrid called parallel recombinative simulated annealing (PRSA). The findings reported in this paper were derived from a large number of tests. About 220,000 test runs were performed over a time period of about 8 months.