Quote Originally Posted by DeathReborn View Post
Can the Memory Controllers on the chips actually operate at those frequencies though? I believe that is where the biggest hurdle lies to date, although I don't know how high AMD can get theirs to run error free.
That does seem to be the problem.
Nvidia had trouble just getting their memory controllers to work at 4Gbps.
AMD had to beef up/tweak their MCs to hit over 4.2Gbps. If I can remember correctly, I am a little sleep deprived right now, I believe in an interview an AMD employee said that they used Redwood's MC in Barts and they are about half the size of Cypress'. Gets you thinking about how much larger Cayman's MCs are compared to Cypress' for only 15% higher bandwidth.

They could just tweak Redwood's MC, stay at the same clocks and with a 384bit bus get a 15% increase in bandwidth over Cayman.