If you have a Crossfire setup, since there is no Catalyst Crossfire profile for it yet you get negative scaling at the moment. You can rename "witcher2.exe" to "dirt2.exe", this will make it use the Dirt 2 crossfire profile. Should give you positive scaling again and a MASSIVE performance increase.
If you can't rename the "witcher2.exe" (eg. Steam edition), you can download a program called Radeon Pro. Add the "witcher2.exe" to it, go to the advanced tab, set Crossfire profile to Dirt2 and move the slider to "Alternate Frame Renderer". Launch the Witcher 2 normally. When a new CAP gets released, just remove TW2 from Radeon Pro.
