TBreak checked out Antilles:

"Since the end of 2010 AMD has successfully launched their 2nd generation DX11 cards from the highest-end HD 6970 to the entry-level HD 6850. AMD’s top-end HD 6970 may have been enough to beat Nvidia’s 2nd tiered GTX 570, but it was still no match for the GTX 580. Ironically the claim to the world’s fastest single card solution was still held by AMD’s very own HD 5970. Last week AMD launched their newest flagship graphics card, the HD 6990."



Link: TBreak