抄録
AMG (Algebraic Multigrid) method is one of the most promising solvers for large-scaled unstructured problems. In this study, the performance of AMG solver has been compared with that of the classical single-grid solver used in GeoFEM; PCG (Preconditioned Conjugate Gradient). The benchmark problems are 2-Dimensional (2-D) steady heat conduction, 3-D homogeneous or heterogeneous penetrative flow and several 3-D elastic problems of FEM. As the result, though AMG requires more memory compare with PCG, AMG is faster than PCG for all large cases which have large degrees of freedom.