Michele Rosso <[email protected]> writes: > Hi, > > I am successfully using PETSc (v3.3) in parallel to solve the Poisson > equation in 3D .
Please upgrade to petsc-3.4 when you get a chance. > The discretization is done by using finite difference on a uniform > structured grid. So far I used the conjugate gradient method, but I > would like to give a try to multigrid. The documentation describes > multigrid as a preconditioner only, thus I would like to know if it is > possible to use multigrid as a solver -ksp_type richardson will not accelerate your multigrid. Krylov with preconditioning is almost never slower, and a lot more robust. > and, if so, if you could give my some tips to start. -pc_type mg -pc_mg_levels 3 -pc_type gamg -pc_type ml -pc_type hypre
