[petsc-users] amg from hypre

[Matthew Knepley]

On Sat, Mar 6, 2010 at 3:41 PM, <hxie at umn.edu> wrote:

> Hi,
>
> I am solving incompressible navier-stokes equations. The code implements
> the Newton iteration and just uses the KSP solver for each iteration. It
> takes 14 nonlinear iterations (~8min) to converge using the default solver
> in PETSc. But it takes 6 nonlinear iterations (~30min) using boomeramg from
> hypre. The amg taks less iterations but takes too much cputime. Is this
> normal? One friend told me the reason may be that I did not call the destroy
> function to free the memory in each Newton iteration (I called PetscFinalize
> after all the Newton iterations). How can I call the PCDestroy_HYPRE from a
> fortran code? Will there be significant difference in cputime to call amg
> directly from hypre? Thanks for any help.
>

This has nothing to do with the memory.BoomerAMG does a lot of processing.

  Matt


> Bests,
> Hui

-- 
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
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