[petsc-users] hypre-boomeramg precondition

[Barry Smith]

On Mar 24, 2014, at 2:54 PM, Qiyue Lu <qiyuelu1 at gmail.com> wrote:

> Dear All:
> 
> I am solving a series of matrix which are from the same FEA model but have different number of meshes. In petsc, I use CR as the solver and hypre-boomeramg as the preconditioner. It works for a small system with 2 million DOFs. Also works for a system with 6 million DOFs. But always fail with an error ' memory out of range' for a 10 or 20 million system. 
> 
> Additionally, with solver CR + preconditioner bjacobi, Petsc could solve 10 and 20 million and even large systems easily. 
> 
> Also, with using top command in linux by monitoring the memory usage, I saw some peaks in the memory.
> 
> So, I am wondering, is this because the memory usage of boomeramg, that larger systems always fail?

   BoomerAMG does require a good amount more memory than “simpler” solvers. There is nothing one can do about it except use more MPI processes with more total memory for larger problems. 

   Barry

> 
> Thanks
> 
> Qiyue Lu