My Setup:
MOBO: GA990FXA-UD7
CPU: FX8150 @ 4GHz
RAM: Dominator 16GB DDR3 1600
GFX Card: 2 Matrix 5870p's, Crossfire @ 930MHz
GFX RAM: 4GB GDDR5 @ 1250MHz
PSU: Corsair AX1200
To fix the issues in Crysis 3, I found that using RadeonPRO BETA 1.1.1.0:
http://www.radeonpro.info/en-US/Blog/7580576579578485512/RadeonPro-Technology-Preview-updated
With SMAASweetFX Injector:
http://forums.guru3d.com/showthread.php?t=368880
Fixes the issues for me. Use RadeonPRO to control the graphics settings and SMAA SweetFX. Do not force Vsync with the program. For me that caused Vsync to not work in Crysis 3. And do not use RadeonPro's overdrive. In Crysis 3 it causes problems. Just stick to the CCC Overdrive.
Also, there is a configurator that was made by one of cryteks R&D engineering people. It is awesome. Works like a charm.
Found here: http://secure.mycrysis.com/forums/viewtopic.php?f=65&t=56955
In using these programs, I have made the game look absolutely beautiful and all the while keeping a steady 60 fps. Runs very smooth, for having everything cranked way above the in game 'Very High' setting. Hope this works.