Satisfiability Test with Synchronous Simulated Annealing on the Fujitsu APlOOO Massively-Parallel Multiprocessor

Solving the hard Satisfiability Problem is time consuming even for modest-sized problem instances. Solving the Random L-SAT Problem is especially difficult due to the ratio of clauses to variables. This report presents a parallel synchronous simulated annealing method for solving the Random L-SAT Problem on a large-scale distributed-memory multiprocessor. In particular, we use a parallel synchronous simulated annealing procedure, called Generalized Speculative Computation, which guarantees the same decision sequence as sequential simulated annealing. To demonstrate the performance of the parallel method, we have selected problem instances varying in size from 100-variables/425clauses to 5OOO-variables/21,25O-clauses. Experimental results on the APlOOO multiprocessor indicate that our approach can satisfy 99.9% of the clauses while giving almost a 70-fold speedup on 500 processors.