Dont get me wrong this is not a what to buy thread

I am planing to mine on a 7970 (Mostly Altcoins).
Since these 3 cards have completely identical Hardware (just different bioses) i am triing to decide wich to use.

Now my question is wich gives me the best performance for mining i used it as a GHz for gaming but wich one is best for mining?
I have tested all of the bioses and they are working perfectly(for gaming).

Sorry for my english guys
(i have posted a similar questions on the doges.org forum but no luck there)