No, first thing is reducing voltage. No need to edit bios for that.
Too late
I flashed 1 gpu using ubermix 3.1 straps (it is a samsung memory)
After that MB won't boot with HDMI connected to it, however it is still being recongnized in windows and capable to mine.
I flashed back its original BIOS, however the display was not fixed.
It is still on warranty so I will return the card.