On Mon, Jul 25, 2016 at 6:17 PM, Ari Rappaport <[email protected]> wrote:
> Hi there! > I am a student intern at Voss Scientific, a contractor for national labs. > I have been researching multigrid methods this summer. My office has an > established particle code which uses petsc libraries for matrix solutions. > There is an interest in using multigrid methods to precondition our > matrices. We have attempted to use the Algebraic Multigrid Preconditioner > on our field solver and it was quite effective with one processor. However, > when we moved to four processors the PCAMG took about 1000 times as many > iterations. Do you mean PCGAMG? > I am wondering if there are any special considerations that need to be > made for using AMG on multiple domains which in turn means multiple > processors? Also, I understand there is also a PCMG option that takes > advantage of the actual grid structure of the problem. I am also wondering > if this could improve preconditioning. > > Thanks, > Ari >
