I use Phoenixminer with -vmr 25.
You need to change these values in OverdriveNtool GPU - P7 - 1300(960mV), Memory - P2 - 2090(930mV), Timing Level - 1 - Level 1, Fan - P0(16)(25) - P1(32)(40) - P2(48)(60) - P3(64)(80) - P4(80)(100), Power - 0.
My card temperature is at 63 C(Room temperature at 30 C) and power usage is 97W.