Edoardo: You can test runtime option '-sub_pc_factor_mat_ordering_type' and use '-log_view' to get performance on different orderings, e.g.,petsc/src/ksp/ksp/examples/tutorials/ex2.c: mpiexec -n 2 ./ex2 -ksp_view -sub_pc_type ilu -sub_pc_factor_mat_ordering_type nd
I do not think the ordering inside block for ilu would affect performance much. Let us know what you will get. Hong Dear users, I have a question about the correct use of the option "PCFactorSetMatOrderingType" in PETSc. I am solving a problem with 2.5M of unknowns distributed along 16 processors and I am using the block jacobi preconditioner and MPIAIJ matrix format. I cannot figure out if the above option can be useful or not in decreasing the computational time. Any suggestion or tips? Thank you very much for the kind help ------ Edoardo Alinovi, Ph.D. DICCA, Scuola Politecnica Universita' di Genova 1, via Montallegro 16145 Genova, Italy email: edoardo.alin...@dicca.unige.it<mailto:edoardo.alin...@dicca.unige.it> Tel: +39 010 353 2540
