[petsc-users] minres and gmres difference

[Jed Brown]

On Tue, Mar 1, 2011 at 14:24, Umut Tabak <u.tabak at tudelft.nl> wrote:

> Yep, then converges, so that you iterate for 146 times(for 155 restart).
> But it seems to me that with a low dimensional subspace it can not catch the
> information. And needs a lot of vectors and orthogonalization which makes it
> costly, are there any further comments?


1. Make a better preconditioner

2. Use a different Krylov method that does not require storing a fully
subspace. Such methods cannot have a monotone residual and are less robust
to inexact Jacobians, but can be better if you need a large number of Krylov
iterations.
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