Aztec: A parallel iterative package for unstructured Grid Problems



R. S. Tuminaro, S. A. Hutchinson, J. N. Shadid

Sandia National Laboratories
Albuquerque, New Mexico 87185

Abstract

We describe a parallel linear system package. This package incorporates a number of novel iterative methods and preconditioners for the solution of linear systems. In this talk we emphasize the parallel programming ease associated with this package even for people who have little parallel computing experience. In particular, a software tool is described that greatly simplifies the parallelization process. The tool transforms a serial matrix description into a distributed matrix suitable for linear algebra kernels used in the iterative solver package. Once the matrix is transformed, AZTEC can be used on the nCUBE 2, the IBM SP2, and on the Intel Paragon. The talk will describe the software tool as well as summarize the iterative algorithms and preconditioners that are available. The major focus of the talk will be to illustrate the significant simplification in parallel programming effort that results from using this software. Additionally, we show that these programming simplifications do not result in a loss of efficiency. In particular, the time for the transformation tool is insignificant and that the iterative methods make good utilization of the machine (i.e. high Gigaflop rates are possible even for sparse matrix applications). Numerous code examples (structured 2D & 3D, unstructured finite element, high order stencils) will be given to support these points.