Yes, I think so; I bet matters on the RHS's and LHS's in the solves are more order one, in the fast case. You can check this yourself of course. ________________________________ From: firedrake-bounces@imperial.ac.uk <firedrake-bounces@imperial.ac.uk> on behalf of Anna Kalogirou <A.Kalogirou@leeds.ac.uk> Sent: Thursday, May 11, 2017 10:13 AM To: firedrake@imperial.ac.uk Subject: [firedrake] Simulation time sensitive to form of equations Dear all, I have noticed that when I divide one of my equations in a mixed system by the time step dt, the simulation time drops by more than half -- from 7m13s to 3m7s for the same simulation. Is there an explanation why this might be happening? Regards, Anna. _______________________________________________ firedrake mailing list firedrake@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/firedrake