Parallelization of Robust Multigrid Methods: ILU Factorization and Frequency Decomposition Method

Using the anisotropic equation as a test problem, the concept of robustness is defined. Two multi-grid methods which are known to have this property are described: the standard multi-grid algorithm with ILU smoothing, and the frequency decomposition method. The parallelization on a MIMD computer is presented, together with results for the speedup obtained. The methods are compared with a standard parallel multi-grid algorithm using a Gaus-Seidel red-black smoother.