[petsc-users] PCHYPRE performance

[Matthew Knepley]

On Wed, Sep 5, 2018 at 4:50 AM Edoardo alinovi <edoardo.alinovi at gmail.com>
wrote:

> Dear users,
>
> I am doing some testing of my FV code, using petsc for the linear systems
> solution. Actually, I am running a small problem (10k cells) in parallel
> with 4 processors. The solution is ok, but I have a question about hypre
> preconditioning performance. I am using PCHYPRE with its default settings
> for the solution of pressure-correction equation. What I am getting is that
> the multigrid  preconditioning is significantly slower than block jacoby in
> solving the equation even if the iteration needed to converge are ten time
> the AMG's one (50 vs 3-4). Is this related to the small size of the problem?
>

It could be the setup time. You could try ML or GAMG to compare, but that
is a little strange.

  Thanks,

     Matt


> Many thanks for the advices,
>
> Edo
>
> ------
>
> Edoardo Alinovi, Ph.D.
>
> DICCA, Scuola Politecnica
> Universita' di Genova
> 1, via Montallegro
> 16145 Genova, Italy
>
> email: edoardo.alinovi at dicca.unige.it
> Tel: +39 010 353 2540
>
>
>

-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20180905/8cba7dbc/attachment.html>