Something I've just noticed regarding bclks.
W3520 - 215
W3570 - 224
W3580 - 224

Interesting... That wasn't on slow mode either.

On another note there must be a clockgen that controls the QPI PPL voltage. Does anyone know where on the board it is? Perhaps a variable resistor might be put in place to increase voltage like on video cards for example. I am not saying it would work but just an idea...