Rob
Ansys Employee
Fluent will try and use as much resource as it needs. That's roughly 2-4GB RAM per 1M cells: models and cell types will effect that value so combustion and multiphase cases tend to use more. You also see good parallel scaling to 10-50k cells per core, again that's model, system and to an extent, geometry dependent. nCores is a difficult one. More cores means more parallel so may be faster but you pay for the licences. However, more cores isn't always faster if the core data transfer isn't also fast. We see too many systems that are throttled on RAM and bus stuff (I break computers: I put electric in one end, and get pictures out the other) n