Multi-Card Scaling In DiRT 2
Nvidia holds on to a lead throughout DiRT 2 testing with its GeForce GTX 570s in SLI, besting the pricier Radeon HD 6970s across the board.
As with all of the tests so far (except Metro), you get playable performance even with two Radeon HD 6870s, though. It’s worth reiterating that it’s probably not necessary to run a pair of graphics cards with this much performance unless you’re spanning a trio of displays in Eyefinity or Surround.
Nvidia might rule the benchmark results in DiRT 2, but the fact that AMD’s cards serve up superior scaling means the GeForce GTX 570’s lead diminishes as you switch from one card to two.