The amount of change your showing (< 1.0e-10) is not unexpected. What solver are you using? If an iterative solver, what's the tolerance? I suspect you are within solver tolerance. You cannot control the order of operations in MPI-based operations so you'll always have some difference near machine precision when running in parallel.
Also recommend you update to the latest version of libMesh. 0.8.0 is getting a little long in the tooth... HTH, Paul On Thu, May 22, 2014 at 12:48 AM, walter kou <[email protected]> wrote: > By the way, this case only contains 8 elements... > > > On Wed, May 21, 2014 at 10:59 PM, walter kou <[email protected]> > wrote: > > > Deal all, > > > > I did a case on solving a LinearImplicitSystem for several steps, and I > > found the result for 2 processor are different with that for 1 processor: > > /***************/ > > 1) case with one processor: ./exe_code > > final residual: 1.50996e-10 Nonlinear convergence: ||delta U|| = > 0.175641 > > > > 2) case with 2 processors: mpiexec -np 2 ./exe_code > > final residual: 1.55163e-10 Nonlinear convergence: ||delta U|| = > 0.175642 > > > > /*************/ > > > > Does that necessarily mean my code has a bug? > > By the way, my version is 0.8.0 > > > > Thanks, > > > > Walter > > > > ------------------------------------------------------------------------------ > "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE > Instantly run your Selenium tests across 300+ browser/OS combos. > Get unparalleled scalability from the best Selenium testing platform > available > Simple to use. Nothing to install. Get started now for free." > http://p.sf.net/sfu/SauceLabs > _______________________________________________ > Libmesh-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/libmesh-users > ------------------------------------------------------------------------------ "Accelerate Dev Cycles with Automated Cross-Browser Testing - For FREE Instantly run your Selenium tests across 300+ browser/OS combos. Get unparalleled scalability from the best Selenium testing platform available Simple to use. Nothing to install. Get started now for free." http://p.sf.net/sfu/SauceLabs _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
