Our tests of the unique dual-processor graphics card from EVGA prove that a dedicated PhysX accelerator is indeed useful and even necessary for comfortable play, but only if the game itself uses the appropriate physics engine. Otherwise, the additional G92b core installed on the EVGA card won’t do anything and won’t have any effect on the card’s performance. As opposed to the GeForce GTX 295, the G92b cannot be used in SLI mode together with the main G200b core.
As we can see in the summary diagrams, the EVGA GeForce GTX 275 CO-OP PhysX is expectedly inferior to Nvidia’s reference card in PhysX-free games due to the reduced frequency of the shader domain. We don’t know why the EVGA card’s shader domain clock rate is lowered. Fortunately, the difference is very small and has no effect on the level of gamer’s comfort. In other words, wherever the ordinary GeForce GTX 275 ensures smooth gameplay, the EVGA GeForce GTX 275 CO-OP PhysX does the same, too. As for the comparison between the unique EVGA solution and Radeon HD 5850, nothing like that is even remotely possible, because the latter is considerably faster in most contemporary games.
There are, however, games (Cryostasis, Dark Void, Darkest of Days and Batman: Arkham Asylum) in which the EVGA card did very well because the auxiliary G92b processor took up all the processing of physical effects, freeing the main GPU’s resources for rendering the 3D scene. The performance gain varies from a modest 13% to an impressive 70%, depending on the game and display resolution. In some situation, this made the difference between whether the game was comfortable to play or not.
You must be aware, though, that there are still rather few PhysX-supporting games due to the exclusiveness of that technology and the efforts Nvidia takes to keep it exclusive. The last and questionable move was the decision to give up supporting PhysX accelerators based on the original Ageia processor in Windows 7. At the time of our writing this review, the list of games that benefit from a hardware PhysX accelerator published at nZone.com names only 16 titles, one of which, Nurien, is not a true game and one more, Unreal Tournament 3: Extreme Physics Mod, is but a modification of an existing game. Then, PhysX effects do not improve in-game visuals as much as to justify the purchase of a PPU, the only exception being the stealth shooter Batman: Arkham Asylum. And finally, if you are really interested in one of the few PhysX-supporting games, you can achieve the same effect by buying and installing an inexpensive Nvidia GeForce GT 220 card which sells for less than $70 in retail. In some cases, a configuration of GeForce GTX 275 and GeForce GT 220 may prove even more effective than an EVGA GeForce GTX 275 CO-OP PhysX. Particularly, it has a considerably higher bottom performance in Cryostasis, making the gameplay smooth and comfortable at resolutions up to 1920x1200 whereas the GeForce GTX 275 CO-OP PhysX cannot do that, notwithstanding its formally more advanced PPU. Besides, this tandem is much quieter than the original product from EVGA.
Moreover, if you use the trick described in this review and combine a GeForce GT 220 with a Radeon HD 5800 series card, you will have even higher performance in PhysX-supporting games. You will also have a much higher speed than with any version of GeForce GTX 275 in all other games. DirectX 11, an HDMI audio core with support for HD formats, and much lower power consumption come as an extra bonus. If this hybrid tandem were more stable, it would easily beat the EVGA GeForce GTX 275 CO-OP PhysX as well as any tandem like GeForce GTX 275/285 + GeForce GT 220/240. Alas, our method is far from trivial and has stability issues, so we can’t recommend it for casual gamers whereas Nvidia keeps on hiding their rather good technology from the masses.
Summing it up, the EVGA GeForce GTX 275 CO-OP PhysX is an exciting product. We have never tested anything of its kind before. But, like with many other solutions with proprietary technologies, its applications and target audience are limited. And in this particular case, the user can achieve the same effect in an alternative way by purchasing any entry-level graphics card from Nvidia that works as a physical effects accelerator, e.g. a GeForce GT 220.
In the majority of games the EVGA GeForce GTX 275 CO-OP PhysX is going to perform just like any other GeForce GTX 275. So, we can only recommend it to users who need PhysX acceleration but cannot afford a GeForce GTX 295 or do not have a free PCI Express x16 slot. The EVGA GeForce GTX 275 CO-OP PhysX will be just perfect for them. But if you don’t play games with PhysX effects, the XFX Radeon HD 5850 Black Edition is going to be a better buy. It is faster, quieter, smaller, more economical and has more advanced functionality than the EVGA card. Additionally, the XFX outperforms the ordinary Radeon HD 5850 due to factory overclocking. And if you want to experiment, you can endow it with PhysX support, but again, we won’t guarantee that such a tandem will be stable and reliable.