Weird (?) results obtained from experiments with the SNESMF module
Matthew Knepley
knepley at gmail.com
Fri Dec 19 16:53:30 CST 2008
On Fri, Dec 19, 2008 at 4:39 PM, Rafael Santos Coelho <
rafaelsantoscoelho at gmail.com> wrote:
> Hey, Barry,
>
> here's what you asked:
You are taking 25K + iterations of GMRES(30). This I think is probably
pretty sensitive to the
exact nature of the FD approximation. Did you try varying the h parameter?
Matt
>
>
> --------------------------------------------------------------------------------------------------------
> JFNK
> KSP SOLVER: GMRES
> MESH SIZE : 512 x 512 unknows
> NUMBER OF PROCESSORS : 24
>
> Linear solve converged due to CONVERGED_RTOL iterations 25042
> Linear solve converged due to CONVERGED_RTOL iterations 33804
> Linear solve converged due to CONVERGED_RTOL iterations 33047
> Linear solve converged due to CONVERGED_RTOL iterations 21219
> SNES Object:
> type: ls
> line search variant: SNESLineSearchCubic
> alpha=0.0001, maxstep=1e+08, steptol=1e-12
> maximum iterations=100, maximum function evaluations=1000000
> tolerances: relative=1e-08, absolute=1e-50, solution=1e-08
> total number of linear solver iterations=113112
> total number of function evaluations=116893
> KSP Object:
> type: gmres
> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt
> Orthogonalization with no iterative refinement
> GMRES: happy breakdown tolerance 1e-30
> maximum iterations=1000000, initial guess is zero
> tolerances: relative=1e-05, absolute=1e-50, divergence=10000
> left preconditioning
> PC Object:
> type: none
> linear system matrix = precond matrix:
> Matrix Object:
> type=mffd, rows=262144, cols=262144
> matrix-free approximation:
> err=1e-07 (relative error in function evaluation)
> Using wp compute h routine
> Computes normA
> Does not compute normU
> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE
>
> Max Max/Min
> Avg Total
> Time (sec): 8.080e+02 1.00009 8.080e+02
> Objects: 6.600e+01 1.00000 6.600e+01
> Flops: 1.044e+11 1.01176 1.036e+11
> 2.485e+12
> Flops/sec: 1.292e+08 1.01184 1.282e+08
> 3.076e+09
> Memory: 5.076e+06 1.01530
> 1.207e+08
> MPI Messages: 4.676e+05 2.00000 3.702e+05 8.884e+06
> MPI Message Lengths: 4.002e+08 2.00939 8.623e+02 7.661e+09
> MPI Reductions: 9.901e+03 1.00000
>
> Object Type Creations Destructions Memory Descendants' Mem.
>
> --- Event Stage 0: Main Stage
>
> SNES 1 1 124
> 0
> Krylov Solver 1 1 16880 0
> Preconditioner 1 1 0
> 0
> Distributed array 1 1 46568 0
> Index Set 6 6 135976 0
> Vec 46 46 3901252 0
> Vec Scatter 3 3
> 0 0
> IS L to G Mapping 1 1 45092 0
> MatMFFD 1 1 0
> 0
> Matrix 4 4 1011036
> 0
> Viewer 1 1
> 0 0
>
> OptionTable: -ksp_converged_reason
> OptionTable: -ksp_max_it 1000000
> OptionTable: -ksp_type gmres
> OptionTable: -log_summary
> OptionTable: -option_table
> OptionTable: -par 4.0
> OptionTable: -pc_type none
> OptionTable: -snes_converged_reason
> OptionTable: -snes_max_funcs 1000000
> OptionTable: -snes_max_it 100
> OptionTable: -snes_mf
> OptionTable: -snes_view
> OptionTable: -xdiv 512
> OptionTable: -ydiv 512
>
> --------------------------------------------------------------------------------------------------------
>
>
> --------------------------------------------------------------------------------------------------------
> NK
> KSP SOLVER: GMRES
> MESH SIZE : 512 x 512 unknows
> NUMBER OF PROCESSORS : 24
>
> Linear solve converged due to CONVERGED_RTOL iterations 25038
> Linear solve converged due to CONVERGED_RTOL iterations 25995
> Linear solve converged due to CONVERGED_RTOL iterations 26769
> SNES Object:
> type: ls
> line search variant: SNESLineSearchCubic
> alpha=0.0001, maxstep=1e+08, steptol=1e-12
> maximum iterations=100, maximum function evaluations=1000000
> tolerances: relative=1e-08, absolute=1e-50, solution=1e-08
> total number of linear solver iterations=77802
> total number of function evaluations=4
> KSP Object:
> type: gmres
> GMRES: restart=30, using Classical (unmodified) Gram-Schmidt
> Orthogonalization with no iterative refinement
> GMRES: happy breakdown tolerance 1e-30
> maximum iterations=1000000, initial guess is zero
> tolerances: relative=1e-05, absolute=1e-50, divergence=10000
> left preconditioning
> PC Object:
> type: none
> linear system matrix = precond matrix:
> Matrix Object:
> type=mpiaij, rows=262144, cols=262144
> total: nonzeros=1308672, allocated nonzeros=1308672
> not using I-node (on process 0) routines
> Nonlinear solve converged due to CONVERGED_FNORM_RELATIVE
>
> Max Max/Min
> Avg Total
> Time (sec): 5.329e+02 1.00008 5.329e+02
> Objects: 6.300e+01 1.00000 6.300e+01
> Flops: 6.553e+10 1.01230 6.501e+10
> 1.560e+12
> Flops/sec: 1.230e+08 1.01230 1.220e+08
> 2.928e+09
> Memory: 4.989e+06 1.01589
> 1.186e+08
> MPI Messages: 3.216e+05 1.99999 2.546e+05 6.111e+06
> MPI Message Lengths: 2.753e+08 2.00939 8.623e+02 5.269e+09
> MPI Reductions: 6.704e+03 1.00000
>
> Object Type Creations Destructions Memory Descendants' Mem.
>
> --- Event Stage 0: Main Stage
>
> SNES 1 1
> 124 0
> Krylov Solver 1 1 16880
> 0
> Preconditioner 1 1
> 0 0
> Distributed array 1 1 46568
> 0
> Index Set 6 6 135976
> 0
> Vec 45 45 3812684
> 0
> Vec Scatter 3 3
> 0 0
> IS L to G Mapping 1 1 45092 0
> Matrix 3 3
> 1011036 0
> Viewer 1 1
> 0 0
>
> OptionTable: -ksp_converged_reason
> OptionTable: -ksp_max_it 1000000
> OptionTable: -ksp_type gmres
> OptionTable: -log_summary
> OptionTable: -option_table
> OptionTable: -par 4.0
> OptionTable: -pc_type none
> OptionTable: -snes_converged_reason
> OptionTable: -snes_max_funcs 1000000
> OptionTable: -snes_max_it 100
> OptionTable: -snes_view
> OptionTable: -xdiv 512
> OptionTable: -ydiv 512
>
> --------------------------------------------------------------------------------------------------------
>
>
--
What most experimenters take for granted before they begin their experiments
is infinitely more interesting than any results to which their experiments
lead.
-- Norbert Wiener
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