Satis ability Test with Synchronous Simulated Annealing on the Fujitsu AP

Solving the hard Satissability Problem is time consuming even for modest-sized problem instances. Solving the Random L-SAT Problem is especially diicult 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/425-clauses to 5000-variables/21,250-clauses. Experimental results on the AP1000 multiprocessor indicate that our approach can satisfy 99.9% of the clauses while giving almost a 70-fold speedup on 500 processors.