On 6/24/10, Jed Brown <[email protected]> wrote: > 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).
Not sure, what do you typically cache ? > 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
