The quality and level of detail of 3D graphics are the number one priority of today’s game developers who try to engage the player’s attention with original visual effects even at the expense of the plot. But besides 3D graphics, there are other factors such as sound or a realistic physical model that help immerse the player into the virtual reality. However, even the basic phenomena of our world that we can see each day around us prove to be extremely sophisticated when it comes to modeling and transferring them into the virtual world. Simulating a flow of water or a realistic flying-off of splinters of broken glass calls for a lot of complex mathematical computations and, consequently, processing resources. Most modern games still utilize the central processor for that purpose but game developers have long had a much more powerful computing device at their disposal because each modern graphics card is in fact a set of numerous unified processors capable of working in parallel.
It must be noted that the idea to free the CPU from physics computations and increase the quality of physical effects in games is not new. In 2006 Ageia, which owned a physical effects engine called PhysX, attempted to launch a new class of coprocessors called physics processing units or PPUs. A PhysX chip, manufactured on 130nm tech process, consisted of 125 million transistors and incorporated a general-purpose core controlling an array of SIMD processors. The PhysX was superior to any CPU at simple tasks that required massively parallel computing such as the modeling of a collision of a lot of objects. Theoretically, this provided an opportunity to improve visual effects such as smoke and fire and even invent new, advanced effects like a real-life simulation of liquids and fabrics or a fully destructible environment. We tested one of the first PPUs in our labs (it was the ASUS PhysX P1) but were not impressed much due to the weak support for the device on game developers’ part, even though some special effects were astonishing indeed.
So, it was all up to game developers. Perhaps, the PPU could indeed make it eventually as a standalone and popular class of devices but on the 13th of February 2008 Ageia with all its innovations was bought by Nvidia which, instead of offering the PPU as a separate product, preferred to endow its GPUs with such functionality instead. As a result, the Ageia PhysX remained the first and only discrete physical effects accelerator. Starting from the 15th of August, 2008, it was replaced by Nvidia’s GeForce 8, 9 and 200 series GPUs. Ageia’s original accelerators are still supported by Nvidia in Windows XP and Vista but not in Windows 7. Anyway, Nvidia’s GPUs are currently the only class of devices that can officially accelerate physical effects in games.
It should be noted that the type of computations required to process physical effects in video games is an ideal match for the architecture of modern GPUs from both ATI and Nvidia. There is only one problem. If one and the same computing core is used for both 3D graphics and physics computations, these tasks will conflict, competing for the GPU’s resources and the GPU may prove to be unable to deliver a high enough frame rate in a 3D scene that is graphically complex and also features advanced physical effects. This problem can be solved by installing a second graphics card into the computer and using it as a PhysX accelerator; Nvidia’s drivers offer this opportunity. But it is not always possible or desirable to install a second card whereas the dual-processor GeForce GTX 295, besides its low availability, has such shortcomings as a high price and a high level of power consumption. And what if an advanced and complex GPU is accompanied with a simple and cheap one, serving as a PPU? That must be the reasoning behind EVGA’s decision to develop and market a unique graphics card that comes with a dedicated PhysX accelerator core. We will test the EVGA GeForce GTX 275 CO-OP PhysX Edition in this review and tell you all about all its highs and lows.
But we mustn’t forget that Nvidia is currently in the position of a technological outsider. In terms of pure gaming performance AMD’s Radeon HD 5800 series, especially the ATI Radeon HD 5850 model, look preferable at a comparable price. But as that model does not support PhysX, it may be hopelessly weak in games that make use of hardware physics effects acceleration, notwithstanding its tremendous computing potential. Nvidia keeps AMD away from the secrets and beauties of PhysX although AMD’s GPUs could be used as physics processing units just as successfully as their GeForce counterparts. This is no good for the PhysX technology itself because, being exclusive, it cannot become really widespread. Game developers just won’t bother to implement innovations that will only be enjoyed by half of the potential audience. We can’t influence Nvidia, of course. But we can go another way and check out if we can endow AMD’s solutions with PhysX support by adding a PPU card from Nvidia. We will also compare the resulting tandem with the EVGA GeForce GTX 275 CO-OP PhysX Edition. Let’s first take a look at the cards we are going to use in this test session.