Good to see that Crysis 3 is Gaming Evolved title as well as TWIMTP.
A quote from a AMD rep in OCN :
Everyone must also keep in mind that Crytek decided to join AMD Gaming Evolved relatively late in the Crysis 3 development process. We've had developers on-site with Crytek around the clock since that point, and we're working together to squeeze every last drop out of Radeon architectures on this title. For example, GCN is one of the reasons Crytek made the switch. It's important to us and them that everything is hunky dory but, compared to other titles at this point in their development cycle, we've all had less time to do that work. So we're doing a little catchup this week and next, applying that spit polish, and making damn sure everything is smooth for launch.