As you’ve just seen in the benchmarks, CrossFire’s key advantage over NVIDIA SLI is ATI’s Super AA performance advantage with the Radeon X1800 XT over the GeForce 7800 GTX cards. ATI’s redesigned compositing engine brings a massive boost to Super AA performance, resulting in little or no performance hit for 8xAA at lower resolutions. In a graphically-intensive game like F.E.A.R for instance, at 1280x960, performance is nearly cut in half for the GeForce 7800 GTX 512MB SLI setup, from 93 fps to just 42. Meanwhile, the X1800 XT CrossFire is cranking along at 51 fps, a drop of just 16%, or 10 fps!
Even 14xAA is quite playable at resolutions as high as 1280x1024 in some games. You can’t really say this for the GeForce 7800 GTX 512MB with 16xAA.
The visuals outputted by both ATI and NVIDIA’s newer AA modes are impressive, particularly when seen while up and running in motion inside games. Jaggies tend to do all sorts of annoying things in motion such as crawling and sparkling. Because of this, our screenshots we’ve provided really only show part of the story when it comes to image quality.
As we noted in our Radeon X1800 CrossFire story though, NVIDIA’s key advantage they have over ATI CrossFire is infrastructure support. Since it’s been around for over a year now, NVIDIA’s SLI ecosystem is not only more mature, it’s considerably more robust as well. You can find SLI motherboards starting right around $100, all the way up to nearly $200, while the boards themselves are often more feature-complete as well. ATI on the other hand only has a handful of CrossFire motherboards on the retail market at the moment, and as such, they tend to sell for higher prices than a comparable nForce4 SLI motherboard.
