Factorized Sparse Approximate Inverse Preconditioning II: Solution of 3D FE Systems on Massively Parallel Computers

An iterative method for solving large linear systems with sparse symmetric positive definite matrices on massively parallel computers is suggested. The method is based on the Factorized Sparse Approximate Inverse (FSAI) preconditioning of ‘parallel’ CG iterations. Efficiency of a concurrent implementation of the FSAI-CG iterations is analyzed for a model hypercube, and an estimate of the optimal hypercube dimension is derived. For finite element applications, two strategies for selecting the preconditioner sparsity pattern are suggested. A high convergence rate of the resulting iterations is demonstrated numerically for the 3D equilibrium equations for linear elastic orthotropic materials approximated using both h- and p-versions of the FEM.