Wattman has three points on the voltage/frequency curve: left, middle and right. The left point at default sits at 800Mhz/800mV.

In the 2019 edition when undervolting (pulling down) the middle point, the left end of the curve would form a plateau at 800mV depending how far you pulled down. The right side of the curve would get steeper.

In the 2020 edition this has changed in that there is no more plateau. The graph always stays a curve and the middle point can't be pulled down as far. The right point can still be set to the same values as before but the curve is less steep on the right side. This means that the further you get to the middle section of the curve the higher the supplied voltage will be.

Depending on where you set your right point this will result in higher voltages than before even at full load. For example:

• My right point is set to 2050MHz@1170mV which is what I tested and found stable with the power target maxed.
• I have since reduced power target again to reduce noise and power consumption.
• My load frequency is usually between 1750 and 1850MHz meaning the 2020 drivers elevating the middle point on the curve raised voltages at these frequencys and resulted in a slight (about 3% in Unigine Heaven) regression in performance

Fix: Using the MorePowerTool I set the minimum graphics voltage to 600mV down from 800mV and have now set my 3 points to:

• left: 800MHz@676mV
• middle: 1425MHz@800mV
• right: 2050MHz@1170mV

I tested for stability by enabling Radeon Chill and setting 80 FPS as min/max value which, depending on the scene, saw clocks fluctuating wildly between 500 and 1900MHz.