It hasn’t taken long for some of Nvidia’s recent acquisitions to bear fruit. Just a few months ago the company got its hands on trailblazing games physics company Ageia. Now it appears the PhysX engine is already running on Nvidia graphics cards.

Kudos to CUDA

The port to Nvidia hardware takes advantage of CUDA, a C programming interface which allows software other than graphics applications to directly address the stream processors on GeForce 8 series and above.

There are over a hundred of these on a top-end GeForce 8 or 9, each one capable of thousands of floating point operations a second. So the potential for calculating physics algorithms (amongst many other things) is immense. Basically, anything which involves lots or repetitive floating point operations could be accelerated by a graphics card.

Nvidia wasn’t the first to announce it was making its GPUs available for wider processing tasks than just 3D acceleration. ATI launched its Stream Computing  initiative in September 2006, closely followed by Close to Metal a couple of months later. The latter brought general purpose computing on graphics processing units (GPGPU) to every day graphics cards.

CUDA was Nvidia’s response. It runs exclusively on GeForce 8 series cards and later (plus their professional Quadro FX siblings). The software developer kit for creating CUDA-powered applications only arrived in February 2007, alongside the Nvidia Quadro FX 4600 and 5600.

A physical future

Both ATI and Nvidia have been talking about running physics on their graphics cards for some time, and even showing off working demos. The implication was that GPUs would exceed the capabilities of dedicated hardware.

Looking at the performance figures quoted by Tom’s Hardware, this is now the case. Nvidia’s presentation mostly focused on how much faster than an Intel multi-core processor its PhysX port was. But it also showed better performance than dedicated Ageia PhysX hardware. Considering Nvidia now owns Ageia, the PhysX hardware looks likely to be seeing the end of the line – which many predicted anyway.

But the news can only be good. It’s hard to deny the potential of hardware physics acceleration. Anyone who has played CellFactor on a PhysX-equipped system will attest to the extra possibilities for fun from a world where you can throw stuff around, send piles of boxes flying, and see cloth fluttering in the wind. It’s another step towards more immersive realism.

In the past, the barrier to more elaborate physics adoption was a classic Catch 22 situation. Games developers were reluctant to harness its full capabilities until enough people had the hardware to take advantage of this. CellFactor is essentially an Ageia-funded technology demo turned into a full game. But gamers weren’t going to buy the hardware until the games supporting it arrived.

Now, however, anyone with a GeForce 8 or later will have the capability. So instead of the reported 150,000 PhysX owners, there will be 50 million Nvidia -owning gamers potentially interested. That’s a much stronger argument for PC games developers.

In other words, Nvidia’s announcement is just what the market needs for physics to make that leap from clever niche to mainstream gaming technology. With 3D graphics now so photorealistic that further enhancements have become boring, physics has the potential to revolutionise gaming again. After all, the real world isn’t just skin deep.