(http://www.gamesas.com/index.php?/topic/1188621-an-update-on-brink/).
In this post he mentions a link to the newest ATI card hot fix(11.5a) that is supposed to resolve some issues and improve performance. The actual truth to the hotfix is that it won't improve fps performance in most cases, actually just the opposite, it will even further lower your FPS because the hot fix isn't about improving performance as much as it is about fixing the system and graphical problems such as the notorious blue Screen, lines on the screen, yellow screen, screen tearing , crashes and so on.
I've tested the new " hot fix " on two different ATI equipped machines and both performed significantly better while running on older legacy ATI drivers. In fact, the new 11.5a hotfix introduced even two new variables, Game and sound stuttering.
I recommend that you test out the legacy drivers, the machine that performed the best before I applied the hotfix was using the 11.2 drivers version but there have been several reports of people downgrading to 10.11 and coming up with exceptional results.
Just a final footnote:
Just because the hotfix does not work for most people you should still give it a try, I came here to inform people that the hot fix is a failure so that they don't rage out after going through all the trouble of reinstalling and updating their drivers just to find out that it was all for nothing.
Edit:
With further research and the help of the forum members it has come to my attention that the 11.5a hotfix might benefit the ones that are using the HD 6xxx series cards but at the same time it might further ruin the experience for people using the 4xxx and 5xxx Ati series cards as my tests showed.
I can only conclude that this hot fix was set up really fast therefor only tested for the latest series which is why it's being called as the "hot fix". I am confident that the ATI team is already working on the 11.6/11.5x version to furthermore add support for legacy cards.