Am Dienstag, 4. November 2014, 19:14:58 schrieb Jed Brown: > Barry Smith <[email protected]> writes: > >> I've tried to use a direct solver like suggested on pp 72, but: > >> > >> ./petBench 600 1 -ksp_type preonly -pc_type lu > > > > You cannot use LU with SBAIJ format. Only Cholesky. So use -pc_type > > cholesky > > And using a sparse matrix format for a dense matrix is a recipe for poor > performance.
I'm more or less aware of that, but I'm surprised that the performance is such poor. I changed the format of matrixC to dense now, but the runtime is still poor. Overall time is now around 9s with 95% spent in KSPSolve and exact the same number of MatMult executions, taking 65% of time. Thx, Florian
