It seems it has something to do with HDMI output and multi-monitor setup. Here are results of my debugging. I have 2x DVI + HDMI connections.
- 2x DVI output - power levels work correctly
- HDMI output only - power levels work correctly
- 2x DVI + HDMI - power levels maxed
For debugging, I’ve only used the bare-bones xorg.conf
VendorName “NVIDIA Corporation”
When X was started with only 2x DVI output, power level were low. When HDMI was plugging in, it becomes available but output remained low.
Aside: xrandr reported HDMI-0 output available, but it would indicate “no such output exists” for a while. Eventually it would start throwing errors. I was only able to active HDMI-0 output via nvidia-settings utility.
When HDMI output was then activated, power level became maxed out. When HDMI is activated (plugged in) at start, they are also maxed.
Disabling the display via
xrandr --output HDMI-0 --off turned off the display but power levels remain maxed.
I will be sending nvidia-bug-report logs to the email@example.com address.