I have headless server with RTX 3090. It is running ubuntu24.04 server (no desktop enviroments). I work with it solely through ssh - no monitor is connected. I am running latest reccomended drivers (550.120) and persistance mode is enabled.
According to nvidia-smi, idle power is around 25w. I assumed this was normal because of the high number of memory chips on the 3090 gpu.
However, today I found out, that when I connect monitor to the server (still no desktop enviroment, just terminal), the power drops to only 13w. It stays this way even after I disconnect the monitor. But when I restart the server, the power is back up to 25w and I have to plug in the monitor again (or re-plug it if I did not disconnected it before restart).
This is reproducible, I tried it multiple times and the power always goes down after the monitor is connected.
EDIT: I tried connecting hdmi edid emulator, which also decreased the power. It seems that the gpu just needs to detect that something new is connected once the OS starts.
EDIT2: Added nvidia bug report tool log.
nvidia-bug-report.log.gz (562.5 KB)