understanding the output from -info

[Barry Smith]

  hypre/boomeramg may be the way to go, especially for the Poisson
problem. -pc_type hypre -pc_hypre_type boomeramg (-help for lots of
tuning options.).

   Barry


On Sun, 11 Feb 2007, Ben Tay wrote:

> Well,
> 
> I am simulating unsteady flow past a moving airfoil at Re~10^4. I'm using
> fractional step FVM, which means that I need to solve a momentum and poisson
> equation.
> 
> To reach a periodic state takes quite a few hours and so I'm trying to find
> ways to speed up the process. I thought parallelizing the code would help
> but it seems like it's not the case.
> 
> I'm now trying out different types of solver/preconditioner available on
> PETSc to assess their performance. Is there other external solvers, which
> PETSc interfaces, which are recommended? I'm thinking of using multigrid to
> solve the poisson eqn... wonder if hypre/BoomerAMG etc would help...
> 
> 
> On 2/11/07, Lisandro Dalcin <dalcinl at gmail.com> wrote:
> >
> > On 2/10/07, Ben Tay <zonexo at gmail.com> wrote:
> > > In other words, for my CFD code, it is not possible to parallelize it
> > > effectively because the problem is too small?
> > >
> > > Is these true for all parallel solver, or just PETSc? I was hoping to
> > reduce
> > > the runtime since mine is an unsteady problem which requires many steps
> > to
> > > reach a periodic state and it takes many hours to reach it.
> >
> > Can you describe your specific application and how are you solving it?
> > As Barry said, your need-for-speed is not likely to be solved by
> > running in parallel.
> >
> >
> > --
> > Lisandro Dalcín
> > ---------------
> > Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
> > Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
> > Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
> > PTLC - Güemes 3450, (3000) Santa Fe, Argentina
> > Tel/Fax: +54-(0)342-451.1594
> >
> >
>