[petsc-users] Suggestion for large scale Poisson's solver

[Barry Smith]

> On May 4, 2017, at 12:52 PM, Hom Nath Gharti <hng.email at gmail.com> wrote:
> 
> Thanks, Barry. Is there a way to take advantage of the fact that the
> matrix remains same during time steps?

   Yes since you are not changing the matrix it will construct the preconditioner once and just use it forever.


> 
> On Thu, May 4, 2017 at 1:47 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>> 
>>> On May 4, 2017, at 12:10 PM, Hom Nath Gharti <hng.email at gmail.com> wrote:
>>> 
>>> Dear all,
>>> 
>>> I am trying to solve a Poisson's equation on the Earth models with the
>>> following information
>>> 
>>> - Degrees of freedom ~300,000,000
>>> - I use MPIAIJ matrix
>>> - Coefficient matrix is symmetric and doesn't change with time steps
>>> - Need to compute for a large number of time steps
>>> 
>>> Which solver/preconditioner is the most efficient for this problem? I
>>> would be grateful for your suggestion.
>> 
>>   Geometric multigrid is always best if you can use it. If not I would use hypre BoomerAMG, it should have very good convergence.
>> 
>> 
>>> 
>>> Thanks,
>>> Hom Nath
>>