Hi Victor, if you decide to use a direct solver and you go into the direction Prof. Banghert hinted, i.e. you decide to use PARDISO: You can access it indirectly to through the PETSC interface of deal.ii. You have to set your -ksp_type to none and your -pc_type to lu and then you can choose Pardiso with -pc_factor_mat_solver_type mkl_pardiso
See https://petsc.org/main/manualpages/Mat/MATSOLVERMKL_PARDISO/ for details. Keep in mind that you need to instruct PARDISO how many cores to use. On many clusters you can do this with exporting the variable OMP_NUM_THREADS If you do not like to use a shared memory PARDISO, you can also use a distributed memory variant called cluster PARDISO https://petsc.org/release/manualpages/Mat/MATSOLVERMKL_CPARDISO/ A sidenote: If you like to use these you to need to compile PETSC such that the solvers are known to it. Best, Nils Victor Eijkhout <[email protected]> writes: > 1. I thought multifrontal solvers are designed for parallelism. But anyway, > since this is external to Deal, it wouldn't use your TaskFlow > threads. > 2. So BlockJacobi doesn't use parallel tasks either? I thought I was seeing > thread activity in my run. > > Ok, so how do I get a parallel preconditioner of higher quality than Jacobi? > Or since this is a time-stepping method, any parallel solver. > > Should I use the Trilinos or PETSc wrappers and implicitly use MPI, even > though I'm on a single node? -- Nils Schween Phone: +49 6221 516 557 Mail: [email protected] PGP-Key: 4DD3DCC0532EE96DB0C1F8B5368DBFA14CB81849 Max Planck Institute for Nuclear Physics Astrophysical Plasma Theory (APT) Saupfercheckweg 1, D-69117 Heidelberg https://www.mpi-hd.mpg.de/mpi/en/research/scientific-divisions-and-groups/independent-research-groups/apt -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/dealii/uo28q9hw3pi.fsf%40mpi-hd.mpg.de.
