Tahar Amari <tahar.amari at polytechnique.edu> writes: > I am not sure I understand your point. I guess you mean that inside > petsc only a version of Gmres working with preconditioning is not yet > implemanted , Am I right ?
I have no idea what Matt intended to say, but all PETSc Krylov methods use preconditioners. However, as Matt and Mark said, multigrid is much better than block Jacobi as a preconditioner for these problems.