Several people myself included have been having issues with some ATI cards in the game. Making this post to get solutions out to the public. None of these seems to be a total solution for everyone, but have been successful for some people. I suggest trying these one at a time,
You can also trying rolling back to the 11.3 drivers
Finally there is the shadow fix which has helped some people out. Go to steam right click brink and find properties/general, look for launch options then put this in the line +com_allowconsole 1 Now go ingame and hit the "`" key next to the one. This will drop down the console type this in. r_shadows 0 This will set shadows off in the game, to check the setting just type r_shadows it'll will give you a value of 1 or 0.
You can't have any sacred cows if you want to make a really great game. Unless you're making a game about killing sacred cows. That's okay. Matt Higby
I am running driver version 10.11 with two 5870s in crossfire. I have had no problems.
I will note, however, that I have had nothing but problems with the version 11.x series drivers from ATI. Every single one has caused a strange 100% utilization on both of my 5870s. Even when on the desktop. I rolled back to 10.11 and haven't had any trouble since.
Tough to get excited about a game that runs at 15-20 fps. Tough to be competitive with that sort of framerate, too.
I don't get why this game runs like complete ass when Crysis 2 ran at maximum settings on my rig at 45 - 60 fps during the most hectic of scenes. Compare that to Brink which I run at the absolute minimum settings (using a config tool to do so) and STILL get completely crap performance.
I really want to like this game, but as of now, I'm shelving it until the performance issues are worked out. I've heard it stems from ATI's piss-poor OpenGL support. So I may wait... forever.