As you can see in the table attached, the GTX 295 is basically a single card made up of two GTX 260, only that it is equipped with a 55nm graphics processor. The core, Shader and memory clocks have been set to 576MHz, 1242MHz and 1GHz, respectively. A total of 1792MB of DDR3 memory will be available for this genuine monster of a card. Also, despite the fact that it basically provides the power of two graphics cards in a single solution, the GTX 295 has a TDP level of just 289W, 53W higher than that of the GTX 280. This feature is mainly a result of the adoption of the 55nm process technology.
Aside from the available technical specifications, the thing that is clearly the most impressive is the performance gap between NVIDIA's upcoming card and AMD's current Radeon HD 4870 X2. According to the slides that have been made available on the it168 website, the GTX 295 is a better solution, enabling a major performance difference in games such as Dead Space, Left 4 Dead or FarCry 2.
The performance level is even higher when games such as Cryostatis and Mirror's Edge are involved. The GeForce GTX 295 can provide close to 80FPS, while the Radeon HD 4870 X2 only manages to score lower than 20FPS in a 1920 by 1200 resolution. The results are influenced by the fact that the aforementioned games utilize NVIDIA's PhysX technology, and that the upcoming cards have been specifically designed to handle it.
The GTX 295 also comes with a better system level power consumption, when compared with that achieved by Radeon HD 4870 X graphics cards.
Source
So it seems to me that as long as games utilize PhysX, which more and more are using, that NVIDIA's cards will have an advantage over the 4870x2.
and right now, AMD is the poor man's brand XD
