[petsc-users] What is the best way to do domain decomposition with petsc?

[Jed Brown]

Matthew Knepley via petsc-users <petsc-users at mcs.anl.gov> writes:

>> I am just wondering which way is better, or do you have any other
>> suggestion?
>>
> If you plan on doing a lot of mesh manipulation by hand and want to control
> everything, the first option might be better.
> On the other hand, if you use Plex, you could potentially take advantage of
> parallel loading and output, redistribution
> and load balancing, adaptive refinement, and interfacing with the
> multilevel and block solvers in PETSc.

There's also a workflow factor.  If you rely on partitioning via Gmsh as
a preprocessing step, then you can't easily run the same mesh on a
different number of processes.  With DMPlex doing the partitioning and
distribution automatically on load (it's fast), you can much more easily
conduct scaling studies, debug configurations, move to different
machines, etc.