Legit Reviews posted a review on the ATI Radeon HD 5870 DX11 Video Card
A quote from the article:
>> ATI Radeon HD 5870 DX11 Video Card Review
Today is the launch of a pair of the most anticipated video cards of all time, the ATI Radeon HD 5870 and Radeon HD 5850! These are the world's first and only DirectX 11 graphics cards, and yes they are out before Windows 7 or a DirectX 11 ready video game has even hit the market. Truth be told, AMD has WHQL certified drivers out for Windows 7 and the new Radeon HD 5000 series is a monster to say the least.
From a performance perspective the ATI Radeon HD 5870 blew away the Radeon HD 4890 and the GeForce GTX 285 graphics cards in the benchmarks that we ran on Windows 7. The Radeon HD 5870 is by far the fastest single GPU graphics card that we have ever benchmarked and it is the real deal. It doesn't have an annoyingly loud fan, suck down obsessive amounts of power or heat up your room while you aren't gaming. The user experience with this card is very well rounded and it is tough to find anything negative to say about it...
>> ATI Radeon HD 5870 DX11 Video Card Review