Re: Speedup in multi-calculation-nodes
already the absolute performance seems to be way too low. A performance of 0.00 MLUPs points to some other problems.
Additionally cavity2d is known to scale quite well even for small grid sizes. For larger grid sizes even strong scaling should be fairly good. One thing that might be a problem for you might be the connection between the nodes. I think we see serious scaling problems if we switch from our infiniband network to our normal ethernet network.
In general I would start inspecting why the parallel version of cavity2d or cavity3d does not scale on your hardware. These examples are known to scale quite well.