Oh ok, understandable since you said everything else is working fine. You got a powerful system. Just for the sake of testing drop the clock speed down a bit you can always bump it back up again. Use the game for a couple days on the lower speed and see how it goes.
I was getting CTD at 3.8Ghz and after taking it down to 3.5 I havent got a single one. Not one. The first and only CTD was in May this year when I bought the game. First tip I found was that it does not like an OC’d CPU.