Hi Bruno,
No, unfortunately I have not played with the parameter values. Hypre has a
set of recommended parameter values for 3D problems, but I think some are
not exposed to the deal.II interface so I have avoided digging into the
source.
I chose PETSc somewhat arbitrarily, so if you are more
Lucas,
it's hard to tell why this might be so slow. In general, I *think* what
you are doing is apply the AMG to the entire, coupled system? That is
unusual, though maybe not strictly wrong. In practice, however, we
almost always apply multigrid preconditioners only to the elliptic
blocks of
Hi folks,
I'm trying to solve a 3D problem in parallel using an AMG preconditioner,
but the performance is bad. I'm wondering if I can get some advice from
someone who has experience choosing and tuning multigrid preconditioners,
particularly for problems in 3D.
For context:
- The problem
