I long realized I'm not the only one with crossfire issues.
Here are my findings on 7970Ghz Cfx, 4670k
Starting scene. Out of the house to the right, right again in the woods, stop before the bridge.
All settings on ultra. Godrays are not necessarily the problem here, but i tested with and without. The offset between tests stays the same so just keep them at whatever you want imho.
Single card: around 50 fps, smooth
Overclocked card: 60 fps, smooth
Crossfire (Standard) 35 fps
Crossfire (Alternate Frame Rendering) 120 fps, light everywhere, everything messed up.
Crossfire (1x1) 35 fps
Crossfire Profiles:
TESV.exe (Skyrim): disables crossfire. 50 fps (duh)
Crysis3.exe: 55-60 fps but with major stuttering
Witcher3.exe 52-53 fps, some stuttering
I am looping in the starting neighborhood doing tests with preset, settings, and tweaks, and i'm not starting the game unless i can get solid performance out of it.
As of now, I haven't.