There’s been something of a glut of gaming physics demos over the last few months, from AMD’s Havok GPU-physics demo to the demos in Nvidia’s latest Graphics Plus Power Pack, but this latest demo of the Infernal Engine’s Velocity physics system adds a new twist – it’s all done on the CPU. Of course, this is nothing special in itself; both Havok and PhysX can run on the CPU too, but it’s amazing what can be done on a CPU with an engine that scales properly over multiple threads.

US tech site [H]ardOCP has just published a number of videos of the Velocity Physics system in action, and it’s impressive to watch in action. The video with the real wow-factor is the Tornado demo. The demo starts off with 1,000 boxes being added to a scene from Ghostbusters: The Videogame, which are shortly followed by 200 soft bodies using ragdoll physics. A tornado is then switched on, swirling the boxes and the soft bodies around so that they interact with the environment. This is impressive enough in itself, but another 2,000 boxes are then added to the scene, and it shows no sign of slowing down.

Of course, the demo was run on a very powerful CPU – a Core i7 with Hyperthreading enabled, but it’s still interesting to see what can be done on a mainstream CPU with an optimised engine. It’s also worth listening to the guy taking you through the demo in the video. “I’m pretty sure we’ve never seen GPU-enabled physics to be able to do anything on a scale like this,” he says, “and our physics engine will scale essentially on an unlimited number of CPUs.” He also adds that “this frees up the graphics card to do the real work that it needs to do, and allows the CPU to really shine.”

If you want to see how the engine scales with more threads, it’s also worth watching the Plinko board demo. The demo shows a number of balls on a Plink board, and starts with just one thread before showing what canm be done using up to eight threads on a Core i7 with Hyperthreading.

Developed by Terminal Reality, the Velocity Physics part of the Infernal Engine promises an array of physics effects. According to Terminal Reality this includes advanced hair and cloth simulation, realistic human body physics with “anatomical joint constraints and simulated muscles/tendons” and advanced dynamic destruction of scenery and environmental objects. The Infernal Engine will also be used as the basis of Ghostbusters: The Videogame.

Would you rather have gaming physics handled by a multi-core CPU, leaving your GPU free for the hard work of graphics rendering, or would you rather use a GPU (or perhaps a second GPU) for hardware-accelerated physics effects? Watch the demo, and let us know your thoughts in the forums.