Report Number: CS-TR-90-1318
Institution: Stanford University, Department of Computer Science
Title: Techniques for improving the performance of sparse matrix factorization on multiprocessor workstations
Author: Rothberg, Edward
Author: Gupta, Anoop
Date: June 1990
Abstract: In this paper we look at the problem of factoring large sparse systems of equations on high-performance multiprocessor workstations. While these multiprocessor workstations are capable of very high peak floating point computation rates, most existing sparse factorization codes achieve only a small fraction of this potential. A major limiting factor is the cost of memory accesses performed during the factorization. ln this paper, we describe a parallel factorization code which utilizes the supernodal structure of the matrix to reduce the number of memory references. We also propose enhancements that significantly reduce the overall cache miss rate. The result is greatly increased factorization performance. We present experimental results from executions of our codes on the Silicon Graphics 4D/380 multiprocessor. Using eight processors, we find that the supernodal parallel code achieves a computation rate of approximately 40 MFLOPS when factoring a range of benchmark matrices. This is more than twice as fast as the parallel nodal code developed at the Oak Ridge National Laboratory running on the SGI 4D/380.