On Thu, Feb 2, 2017 at 12:02 PM, Stefano Zampini <stefano.zampini@gmail.com> wrote:

Mark,

I saw your configuration has hypre. If you could run with master, you may try -matptap_via hypre.

This is worth trying. Does this even work with GAMG?

Treb: try hypre anyway. It has its own RAP code.

It uses BoomerAMGBuildCoarseOperator directly with the AIJ matrices.

Stefano

On Feb 2, 2017, at 7:28 PM, Mark Adams <mfadams@lbl.gov> wrote:

On Thu, Feb 2, 2017 at 11:13 AM, Hong <hzhang@mcs.anl.gov> wrote:
Mark:
Try '-matmatmult_via scalable' first. If this works, should we set it as default?

If it is robust I would say yes unless it is noticeably slower (say >20%) small scale problems.