[petsc-dev] Fwd: [mumps-dev] support for distributed right-hand vectors?

[Alexander Grayver]

On 13.11.2012 14:11, Jack Poulson wrote:
> I can't help but interject. Sparse direct solvers are not nonscalable 
> "in general". General purpose solvers have to worry about pivoting, 
> which greatly complicates the factorization and tends to get in the 
> way of scalability. Several sparse-direct solvers use one-dimensional 
> frontal distributions (e.g., MUMPS and SPOOLES) in order to simplify 
> pivoting, though MUMPS uses a two-dimensional distribution at the root 
> front.
>
> It is well-known how to make multifrontal Cholesky factorization 
> scalable (for example, see one of the many papers by 
> Gupta/Karypis/Kumar/Joshi from the 90's). Making multifrontal 
> triangular solves scalable is another matter.

Jack,

Thanks for the comment.

Could you comment on or give a reference to the blow up in memory one 
observes when running general purpose direct solvers in parallel?

P.S. Does Clique support pivoting?

-- 
Regards,
Alexander