Performance of algebraic multi-grid solvers based on unsmoothed and smoothed aggregation schemes (Q2745522)

The paper gives a detailed comparison of algebraic multigrid solvers AMG0 and AMG1 with respect to computational efficiency when solving discrete elliptic problems. Test cases comprise Darcy flow in a pipe network, Fick diffusion, plane strain linear elasticity, and incompressible flow governed by Navier-Stokes equations. Different mesh types with varying structure, homogeneity, and anisotropy of the grid are considered. The computational efforts for grid generation where AMG0 is cheaper, and solutions where AMG1 needs less iterations, are compared for various test cases and grids. AMG1 turns out to be more robust, and thus superior, for severe problems (e.g. high anisotropy), whereas AMG0 has its advantages in more regular situations and when only modest residual reductions are required.