AMD Radeon HD 6870 Voltage Modifications

The default VDDC sits at approximately 1210 mV. The 200 ohm potentiometer should be a multi-turn type, set at its maximal resistance prior to installation. For better granularity at higher VDDC, use a 100 ohm potentiometer. For less initial voltage gain, try a 500 ohm one.

We do not recommend that you "ground" the potentiometer at any point other than the one illustrated above - doing so would defeat the differential sensing capability of the CHIL8214 Voltage Regulation Module (VRM) controller - and worsen the common mode noise rejection capability of the voltage-sensing amplifier.