AMD And Nvidia: Anti-Aliasing Performance
Rather than re-test all 24 cards over again with multi-sample anti-aliasing enabled, we picked three boards from each vendor representing what AMD and Nvidia consider generational launches.
In AMD's corner, that gives us the Radeon HD 6870, the Radeon HD 5870, and the Radeon HD 4870. In Nvidia's, we're working with the GeForce GTX 580, the GeForce GTX 480, and the GeForce GTX 280.
At 1680x1050, the 6870 and 5870 are on par with AA disabled. Turning 8x MSAA on gives the 5870 a significant advantage, as AMD's Radeon HD 6870 takes a larger performance hit. Interestingly, the 4870's drop isn't as severe, percentage-wise.
The gap narrows at 1920x1080, though AMD's Radeon HD 5870 maintains its lead with 8x MSAA enabled. Sitting pretty at 60 FPS average, that's exactly where we'd want to run the game if we were using a 24" screen.
A 30" monitor demands a 2560x1600 native resolution, and that probably means choosing between smooth frame rates at Ultra quality settings and no anti-aliasing or 8x MSAA and a compromise on the graphics settings. That's not to say that 42 FPS is unplayable, but remember that there are far more demanding (but less repeatable) situations than traveling from one flight point to another.
The Radeon HD 4870 results show us that owners of card with 512 MB frame buffers won't be able to run high resolutions with anti-aliasing enabled at the same time. You'd need a 1 GB board to better measure that combination.
At 1680x1050, the GeForce GTX 580 and 480 are comparable without anti-aliasing turned on. Dialing up to 8x MSAA, however, gives the 580 a sizable advantage. We're similarly CPU-bottlenecked at 1920x1080 sans AA. Yet again, switching it on gives the 580 its advantage. And although the 580 and 480 don't score exactly the same at 2560x1600 minus AA, there's certainly a far greater gap between the two cards once we switch 8x MSAA on.
If you're using an older GeForce GTX 200-series card, the anti-aliased results should be interesting. At all three resolutions, the 280 is less than half as fast as the GeForce GTX 580.