Hi all, I'm trying to run a few scaling tests on the cluster I have acess to. I'm using a mesh with 10,800 elements using an expansion order of 5. The simulation is set to run for 10,000 time steps. The issue that I'm running into is as follows : Doubling the number of processors *increases* the total cpu wall time. *Procs Wall Time* * 1 201 s* *20 209 s* * 40 242 s* I believe this is due to the overhead caused by writing checkpoint files (each parallel stream seems to write a separate checkpoint file). I have reduced the output frequency to the point that only 1 checkpoint file should be written for the entire simulation time, However, this still requires *n *checkpoint files to be written where *n *is the number of processors the case is parallelised on. In all cases I use the mpirun command. For example mpirun -np *n* IncNavierStokesSolver case.xml Could I have some pointers for proceeding further with this issue? Sincerely, -- *Amitvikram Dutta* Graduate Research Assistant Fluid Mechanics Research Lab Multi-Physics Interaction Lab University of Waterloo