Physics has always been part of our games, as the term describes how objects relate to each other and their surroundings. But to render physics in a realistic way, a large number of extremely advanced calculations is required. This demands serious horsepower, which puts more and more strain on the CPU. And as the CPU already handles a lot of other tasks, the idea of a separate hardware unit to take care of physics - just as the GPU handles graphics - has been around for quite a while. Based on that thinking, Ageia created and released their PhysX card. Nvidia and ATI, though, have a different take on the problem, saying that physics can be done just as well, if not better, by adding another GPU to the equation rather than a separate physics processing unit (PPU).

So it seems that opinions differ concerning which technique handles physics best. That's why we here at THG had a talk with a couple of scientists, in an attempt to try to shed some new light on this subject. Is physics really that hard to do? Why? And which technology works best?