[petsc-users] Execution time of superlu_dist increase in multiprocessing

[Barry Smith]

   The time of a direct solver depends on the specific algorithms used by the software and very importantly the nonzero structure of the matrix. We sometimes find that one package scales better than a different package on a particular matrix but then the other package works better on a different matrix. So this is not particularly surprising what you report.

   Barry

On May 20, 2014, at 7:28 AM, 张国熙 <altriaex86 at gmail.com> wrote:

> Hi,
> 
> I'm working on standard eigensolving with spectrum transform. I tried mumps and superlu_dist for ST. But I found that when I run my program  with more process, execution time of mumps decrease, but time of superlu_dist increase. Both of them are called by options like
> 
> char  common_options[]      = "-st_ksp_type preonly -st_pc_type lu -st_pc_factor_mat_solver_package mumps";
> 
> ierr = PetscOptionsInsertString(common_options);CHKERRQ(ierr);
> 
> Shall I set more parameters to get benefit of parallel computing when using superlu_dist? My mattype is mpiaij. 
> 
> Your sincerely
> Guoxi