Introduction

I would like to thank Ageia for providing the review sample

About Ageia

The company can easily be described by one pharagraph found on their China website:

AGEIA Technologies Inc. is a fabless semiconductor company dedicated to delivering pervasive interactive reality to next-generation 3D games. Its flagship product, the PhysX chip, is leading dedicated Physics Processing Unit (PPU) - a completely new hardware category that bridges the gap between virtual worlds in game and responsive physical reality. The PhysX chip allows developers to use active physics-based environments for a more life-like entertainment experience.

Approaches to Physics Processing

Utilizing existing Hardware

Most of us still remember the days of Doom and Wolfenstein 3D, where it did not really matter what kind of graphics card you system was equipped with. System memory and processor speed were the two deciding factors for such old 2D games, which were made to look 3D (thus the term 2.5D). The big era of 3D graphics was the first notable evolution in games and quite a few different companies stepped up to the place to deliver dedicated graphic processing units or GPUs back in the day. The benefits of such a specialized card were obvious when playing the first real 3D games and thus the adoption of such hardware went along fast and without question. In recent years, the 3D aspect - while still important and still being improved - is taken for granted. One aspect which even modern games lack is interactivity and realism within the virtual environment. 3D games used to have unpenetrable, sometimes invisible boundaries in 3D environments, where you could walk to a certain point in a virtual realm, just to be held up by walls or obstacles, forcing the player to take a specific route to finish the level. Thin walls in games were indestructable, while these would never hold up to bullet fire or explosion in the real world.

Real interactivity was always an aspect in games, which designers tried to reach, but never achieved. First attempts were made with scripted interactivity within the virtual realm. Red Fraction is such an example. It boasts the possibilty of destroying certain walls and other items in the game, but was limited to how far and what you could destroy. In recent years with multi core CPUs the question arises if a second, third or fourth core could not be used to calculate real life interactivity within games to make them more realistic. While some game designers have taken that route to enable better artificial intelligence or unload certain tasks from the GPU unto the CPU, Ageia is the first company to actually offer a physics processing unit, or PPU.

While the adoption of GPUs has gone smoothly, as it did bring real and foremost simply implemented benefits, this is not the case with PPUs. The benefits are apparent when playing old games like Quake 1 on two identical systems with and without a dedicated 3D graphic card like the 3Dfx Voodoo. You had better effects with OpenGL back in the day, without a loss of overall performance. All you got were benefits, but no real draw backs. This is not as easy with PPUs as the physics calculations are done to a certain extent by the CPU. Physics computations are not an area which simply did not exist before the release of the Ageia PhysX PPU. The new processor can simply do them better, faster and also take the load off of a CPU, but the extra effects tend to tax the graphic card, thus reducing the overall frame rate delivered.

On the topic of real physic computation, there are generally three camps today.
One believes that such calculations can be done by spare cycles or one of the additional cores of a CPU. Many games do not see a real world benefit when used with a dual or quad core CPU so some wonder if the extra power could not be used for specific tasks like A.I. or physics.
The second group puts their money on GPUs, which are very effective in processing the 3D environments of modern games. AMD and NVIDIA both announced plans to utilize GPUs for such tasks over a year ago. Today's high-end nForce boards even feature three PCIe (x16, x16, x8) slots to fit SLI and an additional card in charge of physics. NVIDIA has also mentioned that even a fairly old GeForce 6600GT should be sufficient for such tasks. Those plans may sound promising and look good on paper, but we have yet to see an up and running implementation which, more importantly, has to have an active support from the development community.

The Ageia PhysX Card - The PPU

The third party believes that a dedicated, independent PPU is the best choice, as you are not bound to a certain platform or chipset, which would be the case with AMD or NVIDIA. The current Ageia PhysX implementation is being sold through ASUS and BFG and we have the former on our test bench today. The overall acceptance of the new processor type has not been as large as some may have thought and there is an explanation for this.

I will go ahead and coin a new phrase here: "First generation PPU enabled games". These are games which came out just before or right after the launch of the Ageia PhysX - so called early adopters. These game developers saw a benefit in the impementation and have actively used it in their games. Some such games are Ghost Recon Advanced War Fighter or Bet on Soldier. The audience was intrigued by the new technology, but was dissapointed by the actual benefit of it. The extra effects in games were not really astonishing and did not feel very natural at all. Another problem was the fact that the extra particles and polygons created due to the physics implementations had a real impact on the performance, as the GPU suddenly needs to render a large number of new particles and effects not present without a dedicated PhysX card.

This is where the "second generation PPU enabled games" come in. One of these games is G.R.A.W 2 or Ghost Recon Advanced Warfighter 2, which we will use to show you how far the dedicated PPU implementation has evolved so far. These are games which had the time to mature and use the Ageia PhysX architecture to a much greater extent than previous titles. The benefits are much more realistic physics effects and hopefully not such a great impact on the overall graphic performance. Another PhysX capable game is the Unreal Engine 3, which we will cover as soon as it is released.