Legit Reviews compared ATI and nVidia under Windows Vista:

In all honesty I'm not impressed by gaming performance on Vista RC1 from what I've seen so far. I'm also a little shocked that ATI sent out a press release in which they quoted an employee saying "ATI continues to introduce shipping-caliber drivers for Windows Vista that improve on the stability, performance and feature set of versions past". I beg to differ with this comment as the latest ATI driver didn't work for us on our test system. Maybe it was the NForce 590SLI chipset's fault or the humidity that is common in Missouri that caused the issues, but whatever the cause it doesn't matter when it comes "shipping-caliber drivers" not to mention that if these are shipping-caliber drivers where is the support for Crossfire? All of the games that we tried playing, over 12 titles in all, were retail games that we purchased with the most recent patches. In case you are wondering about pirated versions working on Vista we don't know because ours were legit.

The purpose of this article was to see how the drivers from ATI and NVIDIA are doing and they are coming along. Neither are what we would call shipping-caliber as both companies lack a ton of features. The NVIDIA drivers don't offer overclocking, GPU temperature monitoring, SLI graphics and many other features that I would call required. I'm a gamer and if my games play ~30% faster on XP Professional then you wont see me switch operating systems till the DirectX 10 titles come rolling out.