On Thu, 24 Jun 2010 13:59:21 -0500 (CDT), David Fuentes <[email protected]> wrote: > > I typically use Petsc Nonlinear Solvers in 3D and my bottle neck is > typically in the assembly with Petsc SNESSolve taking ~10% of the time > about ~50% in the jacobian, ~30% in the residual, and the > rest is distributed.
So the linear solves are really easy. Are you caching a lot of stuff in the residual evaluation, it's not normal for it to be so much compared to Jacobian assembly unless you don't use an analytic Jacobian (e.g. -snes_mf_operator). If residual evaluation can be made cheaper or you are already only assembling a preconditioner, you could probably lag it (-snes_mf_operator -snes_lag_jacobian) to amortize assembly costs. This of course won't change the cost of residuals, but it's usually a good sign (to those of us working on solvers) if you spend most of your time in "physics". Jed ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
