On Thu, Oct 21, 2010 at 23:56, Matthew Knepley <knepley at gmail.com> wrote: > You SNES is not converging. You solve 163 systems, but do 4300 function > evaluations.
That is because the Jacobian is assembled using coloring. Sundials is probably doing fewer steps than BEuler for this problem, and it's also lagging the preconditioner and just using matrix-free differencing to define the Krylov operator. These options are not default with PETSc's TS implementations. Jed
