I have strix 56, using block chain plus overdrive. I dont remember my settings as I am away. Meanwhile what are your clock speeds at various levels? I think I have 1250 odd at 7, mem at 925/950.
it works fine and i put 852/800 cpu and 925/900 mem on level 7 , and 1200w for 7 cards and 275mhs
but only under standard drivers.
when i try the same settings with blockchain drivers i am above 1800w !! don't understand why.