[petsc-users] about ksp

[Jed Brown]

On Mon, Aug 29, 2011 at 10:08, Matthew Knepley <knepley at gmail.com> wrote:

> As I said, no one knows
> how to do this for Krylov methods (and everyone has tried).
>

There are methods and even simply running multiple independent Krylov solves
concurrently would be good for memory traffic (matrix entries get reused for
multiple vectors). The problem with block Krylov methods (that try to share
information between multiple simultaneous solves) is loss of orthogonality
between the subspaces generated by each vector. And it's not so much that
there are no ways to detect and account for this, but robustness is still a
problem and making efficient software for it is more tricky and AFAIK, has
not been done.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110829/05ebb9b6/attachment.htm>