[petsc-users] a direct solver with support for 64-bit integers

[Hari Krishna Kodali]

On 03/24/2010 01:38 PM, Jed Brown wrote:
> On Wed, 24 Mar 2010 13:24:17 -0500, Hari Krishna Kodali<hari at iastate.edu>  wrote:
>    
>> Hi all,
>>
>> I am looking for a parallel direct solver (as my problem is ill
>> conditioned and the petsc provided preconditioners don't help !) that
>> can use 64 bit integers (due to large problem size).
>>      
> I don't have an answer to your question, but what problem are you
> solving that has over 2 billion degrees of freedom, but for which a
> direct solver is remotely feasible?  Or is this a subproblem of a much
> larger simulation?
>
> If you explain the problem, perhaps someone can suggest a way to solve
> the system efficiently with iterative methods.
>
> Jed
>
>    
Thanks for the reply Jed

I have been using superlu_dist and ran into problems.
My two dimensional, structured grid, quadrilateral elements, finite 
element code creates a square matrix of degrees of freedom (dof) 
1,200,000. superlu_dist works fine with this, but when i try a problem 
of dof
1,500,000 there are errors.

The dof is well below 2 billion but the number of nonzeroes in the 
matrix may
have exceeded 2 billion which could be causing the problem.

Thanks

-- 
Hari Krishna Kodali