[petsc-users] Prometheus vs GAMG for elasticity/plasticity problems

[Mark Adams]

And is this just a simple cube problem in elasticity as it looks like from
your input file name?


On Thu, Jan 30, 2014 at 4:40 AM, Thomas Gross <tgross at ilsb.tuwien.ac.at>wrote:

> Please find enclosed the output for GAMG using  -mg_levels_ksp_max_it 1:
>
> Prometheus:
> -ksp_type cg -pc_type prometheus -log_summary -ksp_monitor -ksp_view
> -options_left > Prometheus_Large_Log_New.txt
>
> Gamg:
> -ksp_type cg -pc_type gamg -pc_gamg_type agg -pc_gamg_agg_nsmooths 1
> -log_summary -ksp_monitor -ksp_view -options_left -mg_levels_ksp_type
> richardson -mg_levels_pc_type sor -mg_levels_ksp_max_it 1
> >GAMG_Rich_max_it.txt
>
> Best regards,
> Thomas
>
>
>
>
> On Jan 30, 2014, at 2:14 AM, Jed Brown <jed at jedbrown.org> wrote:
>
> > Thomas Gross <tgross at ilsb.tuwien.ac.at> writes:
> >
> >> I have now compiled Petsc 3.2.0 with Prometheus and Petsc 3.4.3 with
> GAMG using the same compiler. Furthermore I am using the same MPI
> implementation for both runs. Still Prometheus is considerably faster (see
> attached log files).
> >>
> >> Prometheus:
> >> -ksp_type cg -pc_type prometheus -log_summary -ksp_monitor -ksp_view
> -options_left > Prometheus_Large_Log_New.txt
> >>
> >> Gamg:
> >> -ksp_type cg -pc_type gamg -pc_gamg_type agg -pc_gamg_agg_nsmooths 1
> -log_summary -ksp_monitor -ksp_view -options_left -mg_levels_ksp_max_it 1 >
> GAMG_Large_max_it_log_New.txt
> >> -ksp_type cg -pc_type gamg -pc_gamg_type agg -pc_gamg_agg_nsmooths 1
> -log_summary -ksp_monitor -ksp_view -options_left mg_levels_ksp_type
> richardson -mg_levels_pc_type sor > GAMG_Large_Rich_Log_New.txt
> >
> > Can you add -mg_levels_ksp_max_it 1 to this last configuration?  I see a
> > lot of time in MatSOR.  We can actually speed that up slightly with some
> > extra caching, which may be worthwhile.
> >
> > We're seeing a bit lower performance in MatMult with GAMG, perhaps
> > because we are not using block formats specialized for elasticity.
> >
> > Mark, what else is different?  What does Prometheus do differently in
> > setup (not the bottleneck here, but I'm curious).
>
>
>
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