You can play Mafia 2 with a card which is different from nVidia one but the card must be equivalent. A lower graphic card will not behave as nVidia one. On the other hand, Mafia 2 is configured to take advantage of PhysX which is found on nVidia cards.
Software Informer
You can play Mafia 2 with a card which is different from nVidia one but the card must be equivalent. A lower graphic card will not behave as nVidia one. On the other hand, Mafia 2 is configured to take advantage of PhysX which is found on nVidia cards.
AGEIA is the company that created PhysX, a physics runtime. It comes bundled with certain Nvidia Graphics Drivers, or as a standalone install.