Fazlul Huq via petsc-users <[email protected]> writes: > Hello PETSc Developers, > > I am trying to solve a poisson equation using "-pc_type cholesky" and > "-pc_type hypre -pc_hypre_type boomeramg" and I got that cholesky > decomposition method takes > less time then multigrid method. > Is this expected?
For small problems, yes. If using Cholesky in practice, you may want to install SuiteSparse or MUMPS and use -pc_factor_mat_solver_type cholmod (or mumps). > I thought that multigrid method solve faster than cholesky > decomposition method. For sufficiently large problems (especially in 3D), yes.
