On Thu, Sep 3, 2009 at 7:34 AM, xiaoyin ji <sapphire.jxy at gmail.com> wrote:
> Hi, > > Here are the print outs > > for the very beginning, average time is about 0.8sec for the ksp solver > KSP Object: > type: bicg > maximum iterations=10000, initial guess is zero > tolerances: relative=1e-07, absolute=1e-50, divergence=10000 > left preconditioning > PC Object: > type: bjacobi > block Jacobi: number of blocks = 16 > Local solve is same for all blocks, in the following KSP and PC objects: > KSP Object:(sub_) > type: preonly > maximum iterations=10000, initial guess is zero > tolerances: relative=1e-05, absolute=1e-50, divergence=10000 > left preconditioning > PC Object:(sub_) > type: ilu > ILU: 0 levels of fill > ILU: factor fill ratio allocated 1 > ILU: tolerance for zero pivot 1e-12 > ILU: using diagonal shift to prevent zero pivot > ILU: using diagonal shift on blocks to prevent zero pivot > out-of-place factorization > matrix ordering: natural > ILU: factor fill ratio needed 1 > Factored matrix follows > Matrix Object: > type=seqaij, rows=5672, cols=5672 > package used to perform factorization: petsc > total: nonzeros=39090, allocated nonzeros=39704 > not using I-node routines > linear system matrix = precond matrix: > Matrix Object: > type=seqaij, rows=5672, cols=5672 > total: nonzeros=39090, allocated nonzeros=39704 > not using I-node routines > linear system matrix = precond matrix: > Matrix Object: > type=mpiaij, rows=90746, cols=90746 > total: nonzeros=636378, allocated nonzeros=1279114 > not using I-node (on process 0) routines > Norm of error 48.144, Iterations 137 > > After 4000 steps, solver takes 7.5sec > > KSP Object: > type: bicg > maximum iterations=10000, initial guess is zero > tolerances: relative=1e-07, absolute=1e-50, divergence=10000 > left preconditioning > PC Object: > type: bjacobi > block Jacobi: number of blocks = 16 > Local solve is same for all blocks, in the following KSP and PC objects: > KSP Object:(sub_) > type: preonly > maximum iterations=10000, initial guess is zero > tolerances: relative=1e-05, absolute=1e-50, divergence=10000 > left preconditioning > PC Object:(sub_) > type: ilu > ILU: 0 levels of fill > ILU: factor fill ratio allocated 1 > ILU: tolerance for zero pivot 1e-12 > ILU: using diagonal shift to prevent zero pivot > ILU: using diagonal shift on blocks to prevent zero pivot > out-of-place factorization > matrix ordering: natural > ILU: factor fill ratio needed 1 > Factored matrix follows > Matrix Object: > type=seqaij, rows=5672, cols=5672 > package used to perform factorization: petsc > total: nonzeros=39090, allocated nonzeros=39704 > not using I-node routines > linear system matrix = precond matrix: > Matrix Object: > type=seqaij, rows=5672, cols=5672 > total: nonzeros=39090, allocated nonzeros=39704 > not using I-node routines > linear system matrix = precond matrix: > Matrix Object: > type=mpiaij, rows=90746, cols=90746 > total: nonzeros=636378, allocated nonzeros=1279114 > not using I-node (on process 0) routines > Norm of error 48.7467, Iterations 132 > > > The iterations are similar, solving time is actually increasing > exponentially, and the matrix should not be too complicated here as > the PETSc in Fortran solved this in 1sec. > You did not send the output of -log_summary. You will probably have to segregate the solves into different stages in order to see the difference. I suspect a) You do not have something preallocated correctly b) You are not freeing something (run with -malloc_dump) and thus clogging memory c) something apart from PETSc is taking time By the way, will there be a way to set a PETSc vector directly into a > preconditioner for the ksp solver? > Do not know what you mean here. Matt > Thanks! > > Best, > Xiaoyin Ji > > Department of Materials Science and Engineering > North Carolina State University > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20090903/9cc3bda5/attachment.htm>
