[petsc-users] Software for load balancing to improve parallel performance to be used with PETSc

[Jed Brown]

On Mon, Jan 9, 2012 at 13:11, TAY wee-beng <zonexo at gmail.com> wrote:

> Can you explain a bit more about how to adjust the subdomain aspect ratios
> so that strongly coupled cells tend to reside on the same process?
>

You can set the lx,ly,lz in DMDACreate3d().

>
>
>>  using fractional mtd which solves the momentum and Poisson eqns. I
>> construct the linear eqn matrix and insert them in PETSc matrix/vectors.
>> Then I solve using Bicsstab and hypre AMG respectively. Why is PCSetUp()
>> and PCApply using more time?
>>
>
> It is expensive because BoomerAMG setup and apply is expensive.
>
>
> So this is normal? Is there any suggestion to improve performance?
>

This is normal for BoomerAMG. You could use PCGAMG (-pc_type gamg, better
with petsc-dev) or ML (--download-ml, then -pc_type ml) which are algebraic
multigrid methods that are usually less expensive to setup and per
iteration (but sometimes less strong). Geometric multigrid is another
possibility.
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