[petsc-users] block ILU(K) is slower than the point-wise version?

[Kong, Fande]

On Mon, Mar 6, 2017 at 3:27 PM, Patrick Sanan <patrick.sanan at gmail.com>
wrote:

> On Mon, Mar 6, 2017 at 1:48 PM, Kong, Fande <fande.kong at inl.gov> wrote:
> > Hi All,
> >
> > I am solving a nonlinear system whose Jacobian matrix has a block
> structure.
> > More precisely, there is a mesh, and for each vertex there are 11
> variables
> > associated with it. I am using BAIJ.
> >
> > I thought block ILU(k) should be more efficient than the point-wise
> ILU(k).
> > After some numerical experiments, I found that the block ILU(K) is much
> > slower than the point-wise version.
> Do you mean that it takes more iterations to converge, or that the
> time per iteration is greater, or both?
>

The number of iterations is very similar, but the timer per iteration is
greater.



> >
> > Any thoughts?
> >
> > Fande,
>
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