Question for anybody running 6850 CF

One of my 5850s died recently so I swapped them for 6850 CF as a stopgap until the 7xxx series are released. Specifically, I'm running two Powercolour 6850 PCS+ clocked at 875/1160 under Catalyst 11.10 with the latest CAPS and my display is 1080p.

But in Battlefield 3 their performance has been very disappointing. If I want to run even 2x MSAA I have to drop many of the settings down to Medium and for 4x MSAA and SSAO I don't get smooth frame rates even on Medium with Motion Blur disabled.

By contrast, my brother is getting significantly increased performance on a system that is largely identical except for dual 5850s. I know that the 5850 is a faster card, but I was under the impression that when running CF the 6850 tends to beat it because of better scaling.

I am curious as to whether other 6850 CF users have had similar experiences or whether there is a configuration issue or major bottleneck in my system.

AMD cards in general struggle with MSAA, and my 6870 CF setup seemed to struggle with 4x MSAA. I can run max settings with 2x MSAA and stay at 60fps almost perfectly. I was having some trouble changing settings though, and when I would change it to 4x MSAA, it would crash sometimes, or my fps would just drop like a rock. I need to do some more testing, but be aware that AMD cards in general really struggle with MSAA, and our cards really don't have enough vRAM for 4x MSAA.

Uninstall any AMD Performance Packages listed in your Installed Programs list.

Uninstall all other AMD drivers and re-install 11.10 from scratch. Restart.

Then install the CAP4 profiles. Restart.

Voila.

Thanks, working fine now