AMDZONE.IT | Utility | Informazioni e Release Notes

** A few important notes for RADEON VII owners:

Core voltage slider in MSI AB is supposed to be locked on RVII, that’s normal and by design. On the previous AMD GPUs the slider provided direct voltage control mode implemented via low-level access to SMC or voltage controller (slider position defined either full target voltage override or P-State independent voltage offset) and such voltage adjustment form was required because native AMD driver’s voltage adjustment range was too low. On RVII series cards AMD driver allows up to 1.2V overvoltage (from default 1V) and voltage control is provided in MSI AB at voltage/frequency curve editor level. So simply open the editor (either press VF editor button in the skin next to core clock slider or hit <Ctrl>+<F> keyboard shortcut to open the editor) and you’ll be able to adjust voltage there.
Temperature limit slider is also supposed to be locked by design on RVII, it was a part of old AMD fan control algorithm. It is gone with Adrenalin 2019 drivers family when fan curve adjustment approach was introduced by AMD. So it is no longer adjustable in AMD driver and supposed to be locked now.
Voltage/frequency editor is allowing you to adjust frequencies and voltages independently for all 3 V/F curve points (or 3 P-States), however AMD driver and RVII architecture put some restrictions on the curve editing approach. So the curve will be corrected according to the following limitations when you apply it:

You can adjust the frequency independently for the first and the last point only. Middle point frequency cannot be adjusted independently, frequencies are always linearly interpolated from the first point to the last point. So if you try to adjust frequency for the middle point, it will be corrected according to interpolation rule mentioned above right after applying new settings
Unlike the frequencies, you can independently adjust voltages for all 3 points
You cannot set frequencies and voltages below the minimum (which is rather strict and very close to default). This puts some limitations on lower P-State downclocking/downvolting
2 GPU temperatures displayed by MSI AB hardware monitoring module are mapped to edge and junction temperatures. 4 displayed VRM temperatures are mapped to core VRM, SOC VRM and 2 memory VRM sensors. AMD’s fan curve is using junction temperature for their fan speed adjustment. I’m not sure if it is really good idea because it is skyrocketing to 100C area pretty rapidly when GPU is busy, that’s actually direct reason why RVII cooling is so loud by default. Opposing to that, MSI AB’s software fan curve implementation is still using traditional edge temperature sensor. Probably I’ll add an ability to select input thermal sensor for software fan curve adjustment in future versions, but honestly I’m not sure if it worth the efforts
Currently AMD's own GPU usage sensor is suffering from pretty bad 0%->100%->0% fluctuations. Similar issues affected some old GPUs in the past but it is much worse on RVII now. I believe that it is what they mean with "Performance metrics overlay and Radeon WattMan gauges may experience inaccurate fluctuating readings on AMD Radeon VII" in the driver's known issues, so there is a hope to see a fix from AMD in future. I remind you that it is possible to get rid of such fluctuations via enabling unified GPU usage monitoring in MSI AB properties, however this option depends on DirectX GPU usage performance counter and this counter requires OS and display driver WDDM versions to match. Current AMD drivers are targeted to WDDM 2.5 OS (October Update), so this option will only help you if you have 1809 OS version installed. Otherwise you'll see zero GPU usage all the time after enabling it.