Re: [Libmesh-users] Quick question - bandwidth minimization?

[Yuxiang W. <yw...@vi...>]

John & Jed,

Got it! Thank you so much for the help.

Best,
Shawn

On Thu, May 2, 2019, 11:04 Jed Brown <je...@je...> wrote:

> John Peterson <jwp...@gm...> writes:
>
> > On Thu, May 2, 2019 at 12:35 PM Yuxiang Wang <yw...@vi...> wrote:
> >
> >> Dear all,
> >>
> >> A quick question - when using libmesh, should I consciously do bandwidth
> >> minimization when I number my node IDs? Or, are those taken care of at
> >> pre-processing stage of PETSc and other solvers?
> >>
> >
> > I wouldn't try and do anything manually since PETSc has a number of
> > renumbering algorithms that I think you can play around with pretty
> easily
> > to see if they make any difference...
>
> You can run factorizations in a different ordering, but low-bandwidth
> orderings make a difference for cache reuse in MatMult.  PETSc can't
> reorder that without making a copy.  But don't put too much effort into
> it.
>