[petsc-users] HYPRE hanging or slow? from observation

[Matthew Knepley]

On Sat, Oct 21, 2017 at 5:04 PM, Hao Zhang <hbcbh1999 at gmail.com> wrote:

> hi,
>
> I implemented HYPRE preconditioner for my study due to the fact that
> without preconditioner, PETSc solver will take thousands of iterations to
> converge for fine grid simulation.
>
> with HYPRE, depending on the parallel partition, it will take HYPRE
> forever to do anything. observation of output file is that the simulation
> is hanging with no output.
>
> Any idea what happened? will post snippet of code.
>

1) For any question about convergence, we need to see the output of

  -ksp_view_pre -ksp_view -ksp_monitor_true_residual -ksp_converged_reason

2) Hypre has many preconditioners, which one are you talking about

3) PETSc has some preconditioners in common with Hypre, like AMG

  Thanks,

     Matt


> --
> Hao Zhang
> Dept. of Applid Mathematics and Statistics,
> Stony Brook University,
> Stony Brook, New York, 11790
>



-- 
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.caam.rice.edu/~mk51/>
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