PC demo Lagging With APEX/PHYSX settings

[wiseguy50]

Alright I am looking forward to playing Mafia II on my Asus G73 gaming laptop. My specs are:
Intel Core i7-720QM processor (1.6GHz/2.8GHz Turbo Mode,
ATI Mobility Radeon HD 5870 1GB GDDR5 graphics card
8GB DDR3-1066 RAM
Two 500GB 7200RPM hard drives

Now the problem is when I turn on APEX in the demo to medium or even high the game starts to lag and is very slow also the fps is affected. Now would I encounter these problems with the final retail version also will I not be able to enjoy the physX features because of not having an NVIDIA graphics card? I know my laptop can handle the game extremely well for a fact. So any one know why with the APEX settings on the demo becomes sluggish and with low fps?

[Kleetus]

When you use an ATI card/chip and enable PhysX, all the processing is done by your CPU, instead of the GPU in nvidias case.

Solution: Don't enable PhysX.

[wiseguy50]

Thank you Kleetus I guess I wont be using and enjoying physX then.

[Daz1967]

How simple would it have been to have actually had a warning for non-NVIDIA graphics card owners that switching the APEX PhysX setting to Medium or High would massively affect the framerate because it is ran on the CPU not GPU? In fact, single NVIDIA card owners should also get a warning too because users with mid or low-range cards will also suffer framerate issues if they use it.

Didn't the developers even consider that or is it because everything is expected to play this game with high-end multiple NVIDIA graphics hardware?