Mafia 2 PhysX: CPU Core Use

With a clear indication we're CPU limited no matter what graphics card we used when PhysX ran on the CPU - we fired up the Radeon HD 5870 (so eliminating any possible driver trickery between an Nvidia GPU and its PhysX) and we checked to see how using different numbers of cores and extra frequency affected the result.


With a Intel Core-i7 980X we got a rather puzzling, but consistent result with 6-cores at the high setting. We ran this test again and again but it consistently popped out an average frame rate of 13fps when high PhysX detail is used, so we can only conclude it's down to a driver bug in the high setting.

As we've seen many times in games recently it appears that 3-cores or more is enough for the Mafia 2. This gives the OS one core to do its bit in the background and the game another two to spend how it likes. While there's a slight jump at the medium setting with 6-cores the performance is mostly plateaued out after three.

PhysX on (high setting)

PhysX off

Mafia 2 PhysX: CPU Frequency Use

Adding frequency to (an already fast) Core-i7 980X CPU gives us a healthy boost all round. Evidently even with PhysX disabled the game is not CPU limited as the overclock has no appreciable gain in FPS. With high and medium PhysX settings there's an obvious advantage though with both benefiting from very similar gains regardless of rendering graphics card. Clearly then with CPU PhysX enabled Mafia 2 is indeed CPU limited - we need even more frequency! MOAR MHz!

With such large gains in those results, we went back to see how overclocking the CPU affected other setups with PhysX running on GPU. But not before we checked out the unofficial way of doing things...