[petsc-dev] Test Problem Recommendations

[Nystrom, William D]

Thanks.  I'll give these try.  It is interesting to look at your results for the
3d ice flow problem.

Thanks,

Dave

--
Dave Nystrom
LANL HPC-5
Phone: 505-667-7913
Email: wdn at lanl.gov
Smail: Mail Stop B272
       Group HPC-5
       Los Alamos National Laboratory
       Los Alamos, NM 87545

________________________________
From: petsc-dev-bounces at mcs.anl.gov [petsc-dev-bounces at mcs.anl.gov] on behalf of Jed Brown [jedbrown at mcs.anl.gov]
Sent: Friday, January 20, 2012 3:12 PM
To: For users of the development version of PETSc
Subject: Re: [petsc-dev] Test Problem Recommendations

On Fri, Jan 20, 2012 at 16:03, Nystrom, William D <wdn at lanl.gov<mailto:wdn at lanl.gov>> wrote:
I'm getting ready to use petsc-dev as part of our test suite for doing
stability testing of some new hardware platforms with gpus.  I'm
interested in testing both with and without using gpus.  So far, I have
not extensively explored the various example problems that come with
PETSc.  Mainly, I have run src/ksp/ksp/examples/tutorials/ex2.c

This is a horrible example because the parallel decomposition is 1D. You can run essentially the same model with a better decomposition (and inside a nonlinear problem) with src/snes/examples/tutorials/ex5.c (which can also do geometric multigrid, but you don't have to use it).

which is a 2d Laplace's equation problem.  I'm looking for recommendations
of PETSc example problems that I should try, especially ones that might
be more challenging numerically than ex2.c or more realistic of real
world problems.  Does anyone reading this email have a favorite PETSc
example problem that you would suggest I consider and try?

Here are some options and profiling output (on a BG/P) for a 3D ice flow problem (src/snes/examples/tutorials/ex48.c):

https://github.com/jedbrown/tme-ice/tree/master/shaheen/b


src/ksp/ksp/examples/tutorials/ex43.c (2D Stokes, preconditioned using fieldsplit inside multigrid)

mpiexec -n 8 ./ex43 -stokes_ksp_type gcr -stokes_ksp_gcr_restart 60 -stokes_ksp_norm_type unpreconditioned -stokes_ksp_rtol 1e-8 -c_str 3 -sinker_eta0 1.0 -sinker_eta1 100 -sinker_dx 0.4 -sinker_dy 0.3 -mx 1024 -my 1024 -stokes_ksp_monitor -o sc1024.dat -stokes_pc_type mg -stokes_mg_levels_pc_type fieldsplit -stokes_pc_mg_galerkin -stokes_mg_levels_pc_fieldsplit_block_size 3 -stokes_mg_levels_pc_fieldsplit_0_fields 0,1 -stokes_mg_levels_pc_fieldsplit_1_fields 2 -stokes_mg_levels_fieldsplit_0_pc_type sor -stokes_mg_levels_ksp_type chebychev -stokes_mg_levels_ksp_max_it 1 -stokes_mg_levels_ksp_chebychev_estimate_eigenvalues 0,0.2,0,1.1 -stokes_pc_mg_levels 5 -log_summary


src/ksp/ksp/examples/tutorials/ex56.c (3D elasticity, process count should be 8^n)
mpiexec -n 64 ./ex56 -ne 255 -alpha 1.e-3 -ksp_monitor_short -ksp_type cg -pc_gamg_type sa  -ksp_norm_type unpreconditioned -pc_gamg_verbose -pc_gamg_repartition -pc_gamg_process_eq_limit 10 -pc_gamg_coarse_eq_limit 20 -pc_gamg_mat_partitioning_type ptscotch -log_summary -pc_gamg_mat_partitioning_ptscotch_strategy scalability
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