Topic of discussion for many weeks now is that AMD has been applying a series of optimizations that could easily be seen and explained as a cheat. Currently with the Radeon HD 6000 series release the Catalyst drivers (Catalyst AI) have a new setting which allows control over control texture filtering with settings for 'High Quality', 'Quality' and 'Performance'.
Let's have a quick look at what it means, but most of all, what to look for and what performance effect it has in this quicky small article.
You can read the article here.