As expected the Radeon HD 5970 is vastly superior to the GeForce GTX 295 in terms of performance beating it in every single test, at all tested resolutions.
On average the Radeon HD 5970 was 53% faster than the GeForce GTX 295 at 2560x1600. Even removing the top three tests where the Radeon led with the biggest margins (BattleForge, Enemy Territory and Street Fighter IV), the HD 5970 still ended up some 34% faster than the GTX 295.
It's easy to conclude from there that the Radeon HD 4870 X2 presented no contention whatsoever, and that ATI's latest dual-GPU Radeon can claim the title of the fastest graphics card currently in the market.
Another interesting statistic is that the Radeon HD 5970 was on average 46% faster than the Radeon HD 5870, while costing 50% more. Assuming that you can increase the core frequency of the Radeon HD 5970 by at least 17% and the memory by 20%, then you can effectively produce a pair of Radeon HD 5870 GPUs in a single board. Once again, for those who can justify the price, we feel that the Radeon HD 5970 provides enthusiast users with a viable alternative towards extreme performance.
It should be noted that under load the Radeon HD 5970 operated at an acceptable volume when running at its default specifications, but this wasn't the case when overclocking. In order to keep the GPUs at safe temperatures, the blower fan was working overtime and in the process created so much noise it was impossible to hear myself think. Those looking into overclocking the already super-fast Radeon HD 5970 will need to delve into alternative cooling methods such as water.
The Radeon HD 5970 is also the largest graphics card we've ever tested with a length of 30cm, it's larger than the 4870 X2 or the GTX 295. This card is not going to be compatible with a wide range of computer cases, so those looking at purchasing it should first make sure their case can accommodate for the EATX (extended ATX) form factor, which measures 30.5cm wide, or roughly the same dimension as the Radeon HD 5970.
Like all multi-GPU graphics cards, the Radeon HD 5970 relies heavily on driver support to perform as intended. Every time a new game is released it is likely that the Radeon HD 5970 will not fully support it (taking advantage of the two GPUs) until AMD updates the Catalyst driver. I'm usually skeptical about multi-GPU technology as the results tend to vary a lot, though admittedly things have improved considerably from where we were a year ago.
Without full Crossfire support the Radeon HD 5970 will perform somewhere in between a single Radeon HD 5870 and 5850 graphics card, which is still pretty decent.
Make it official, the Radeon HD 5970 is the fastest graphics card in the market, outperforming by a long shot previous generation dual-GPU products. We can't decide for you whether it makes sense to spend $600 on this graphics card or not, but at least it's nice having the option.
The next step for AMD/ATI is not to work on their next-generation products, as it is making sure the current Radeons are widely available from retailers. We sure hope the Radeon HD 5970 does not become a soft launch, following the inventory debacle seen with the rest of the series. So, inventory first and working around the drivers' rough edges should make this a great purchase for those who can afford it.