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The SSOR preconditioned conjugate-gradient method on parallel computers

Thesis/Dissertation ·
OSTI ID:6473075
In this dissertation we consider the efficient implementation of iterative methods for solving linear systems of equations on two types of parallel computers: message passing systems, exemplified by the Intel iPSC/1 Hypercube, and local/global memory bus connected systems, exemplified by the Flex/32. The iterative methods being studied are conjugate gradient and m-step SSOR preconditioned conjugate gradient. The class of problems that we are studying are large sparse linear systems of equations arising out of structural analysis problems. We discuss partitioning of the problems to the processors, and present algorithms for efficient implementation of the matrix-vector multiply and the forward and back solves in SSOR for a general symmetric matrix. One way to implement the SSOR preconditioning step is through the use of a multicolor ordering of the unknowns. We will present an algorithm that we have developed to do the multicoloring. To speedup the preconditioned conjugate gradient method for one-step preconditioning, we used three methods for reducing the amount of work per iteration and compared them. We have also extended these methods to m steps of the preconditioner and have analyzed them and compared their performance.
Research Organization:
Virginia Univ., Charlottesville, VA (USA)
OSTI ID:
6473075
Country of Publication:
United States
Language:
English