X-bit labs

AGEIA PhysX Physics Accelerator Review

Category: Video

by Alexey Stepin , Anton Shilov

[ 06/23/2006 | 11:18 AM ]

AGEIA PhysX. What stands behind this name? Is it a revolutionary solution that provides unbelievable realism in computer games or a beautiful but useless toy? Today we are going to try answer this question, because the so long awaited by many computer enthusiasts physics accelerator has finally found its way into our lab.

Table of contents:

• Technical Specifications of AGEIA PhysX
  
• Working Principles and Possible Limitations
  
• Support in Games: Is It a Bottleneck?
  
• ASUS PhysX P1: PCB Design and Cooling System
  
• Testbed and Methods
  
• Performance
  
• Tom Clancy’s Ghost Recon Advanced Warfighter
  
• CellFactor Demo
  
• Hangar of Doom Demo
  
• AGEIA Control Panel Demo
  
• Conclusion
  
• Market Prospective
  
• Impressions from AGEIA PhysX PPU
  

Besides color, shape and smell each object in this world has a dozen of physics characteristics such as weight, density, elasticity and others that affect their behavior when these objects interact with other objects or people.

The rubber ball jumps off the floor, the water fills the gaps, the bomb ruins the wall, the fragments of broken glass scatter all over – there are millions of examples like that in our everyday life. However until recently nothing like that could be seen in computer games that were developed to model physical world – real or fictitious. The player could unload his entire reserve into the wooden barrel or thin building wall, but the barrel will remain their as solid as before and the wall will in the best case have a few tracks left by the bullets emulated with textures.

The game developers have lately achieved quite impressive results with the virtual words visualization, since the graphics cards have become much more powerful. It has become possible to demonstrate extremely complex scenes without fearing that the game would turn into a slide show. This has certainly added more realism to the games of today compared with what we saw 5 years ago, for instance. However, the realistic feeling you get from the game builds up from multiple factors. One of them is the interactivity of the game world, and it is certainly not less important than photorealistic graphics. The interactive character of the world in the game has always been a very tough nut to crack.

The thing is that accurate emulation of the objects’ behavior using real-life physics requires a lot of computational power. If it possible to implement the behavior emulation for a relatively small number of objects, which has been done in Half-Life 2 in particular, then the emulation of real physics for all objects of the scene can easily stall even the most powerful CPU. Yes, today it is the CPU that bears the complete workload of the physics models calculations in the games. When dual-core processors appeared it looked like it was possible to assign one of the cores to this complex task, while the other core would continue working on the game A.I., pathfinding, etc.

This logical solution is though just a semi-measure: the specifics of modeling complex objects and particle systems for such phenomena as smoke, water, etc. requires a lot of parallel calculations, otherwise the performance may turn out unsatisfactory. In other words, we need a computational device with parallel architecture that can quickly process a number of complex calculations if we want to be able to implement a complex realistic physical model in the today’s games. I have to stress that contemporary GPUs or CPUs like Cell, for instance, have exactly the architecture like that. Moreover, ATI Technologies and Nvidia have already announced the ability of their Radeon X1000 and GeForce 7 graphics cards to work as physics coprocessors.

A small and relatively young company , AGEIA Technologies, founded in 2002 has been long working on a special PhysX co-processor designed to process calculations of the physical models in contemporary games. The first solutions based on this chip have recently hit the streets. We are going to take a closer look at this new solution and ASUS PhysX P1 card will help us here.

So what does this physics accelerator from AGEIA Technologies look like?