SLI vs. Crossfire: Which is King?
When we compared the GeForce GTX 480 and the Radeon HD 5870 as single card solutions we gave the nod of approval to the Radeon for a few simple reasons. Even though the GeForce was faster, it's also more expensive and too power hungry, making it a less practical option. The Radeon HD 5870 on the other hand is almost as fast, it's a better value per dollar, and much more fuel efficient.
Still there are those who will be looking to purchase not one but rather two high-end graphics cards, taking the GPU budget from the $400-500 range to nearly a thousand bucks. In this situation, we saw an opposite direction with Nvidia claiming the crown of who is who in the PC graphics world.
In our tests ATI’s Crossfire technology didn't scale nearly as well as Nvidia’s SLI technology. Although historically we have seen far worse results from dual GPU configurations, in this ocassion Crossfire provided with an average frame per second improvement of 62%. That is, doubling down your investment on a Radeon GPU will provide you with that kind of performance boost.
Then we have the GeForce GTX 480 SLI cards which cost ~25% more than the Radeon HD 5870 Crossfire graphics cards. However these cards were able to scale considerably better providing an average of 90% more performance when gaming at 2560x1600 in the games we tested. When you consider that the GeForce GTX 480 was already a bit faster than the Radeon HD 5870 in most games, and then adding a second graphics card to each configuration favored the GeForce GTX 480 by almost 30% things start to add up.
With the exception of Crysis Warhead (8xAA) and Metro 2033 (4xMSAA/16xAF/Tessellation) which didn't run correctly on the ATI platform, we found that the GeForce GTX 480 SLI setup delivered on average 34% more performance than the Radeon HD 5870 Crossfire graphics cards.
Granted the major victory was had when testing with Metro 2033 and Tessellation enabled, where the GeForce GTX 480 SLI setup was 94% faster. The Nvidia cards still provided just over 20% more performance in newly released games such as Aliens vs. Predator and Battlefield Bad Company 2. The GeForce GTX 480 SLI cards were just 6% faster when testing with Just Cause 2 and 18% faster in Metro 2033 with Tessellation disabled.
Even if you remove the extreme scenarios the GeForce GTX 480 SLI cards were ~20-25% faster than the Radeon HD 5870 Crossfire cards which covers the pricing gap.
Before we wrap things up we must touch on the power figures as they were a little disturbing when looking at the Nvidia cards. Our test system was consuming 787 watts under full load which is incredible, even more so when you consider that this was 33% more than the Radeon HD 5870 Crossfire cards. Most small room heaters only consume ~1000 watts of power, so essentially a GeForce GTX 480 SLI system can serve two purposes, the second of which will likely be welcomed during winter months.
Even the most addicted of gamers will not spend all their time playing games, and this is why the idle consumption of 348 watts is also a little scary. This means that from the moment you boot up to the moment you shut down your computer, it will have consumed no less than 348 watts at any given time.
Regardless of this, if you can handle the power requirements then SLI is the way to go for your high-end dual GPU needs. For the lower-end cards we find it harder to go past a pair of Radeon HD 5770 Crossfire graphics cards as they outpace contenders such as the GeForce GTX 470 and Radeon HD 5850. However for those seeking the ultimate high-end experience we highly recommend checking out a GeForce GTX 480 SLI setup.