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

[Patrick Sanan]

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?
>
> Any thoughts?
>
> Fande,