[petsc-users] Benchmarking

[Jose E. Roman]

> El 28 dic 2016, a las 17:14, Vijay Gopal Chilkuri <vijay.gopal.c at gmail.com> escribió:
> 
> Dear Jose,
> 
> Thanks for the references.
> 
> I'm only calculation the smallest 10-100 eigenvalues using the krylovshur algorithm.
> 
> How important is it to use a preconditioner ? My matrix has at most 48 nonzero elements per row.
> 
> 

With Krylov-Schur you don't need a preconditioner if computing smallest-real eigenvalues (which I think is your case). Preconditioners are relevant only for interior eigenvalues (chapter 3 of the users guide).

Jose