Does Nvidia GPU send data through HDMI when monitor turned off?

Question

Linux Mint 20 Cinnamon. NVIDIA 1060 Max-Q, driver 440.
Windows 10 Pro build 2004, NVIDIA driver 451.

If I power off my TV, connected with HDMI 2.0, or even start the laptop with it turned off, it seems still being detected by my laptop:

$ xrandr --current

# TV snippet
Screen 0: minimum 8 x 8, current 3840 x 2160, maximum 32767 x 32767
HDMI-0 connected 3840x2160+0+0 (normal left inverted right x axis y axis) 708mm x 398mm
   3840x2160     60.00*+  59.94    50.00    29.97    25.00    23.98  
   4096x2160     59.94    50.00    29.97    25.00    24.00    23.98  
   1920x1080     60.00    59.94    50.00    29.97    23.98    60.00    50.04  
   1440x900      59.89  
   1440x480      60.05  
   1280x1024     60.02  
   1280x720      59.94    50.00  
   1024x768      60.00  
   800x600       60.32  
   720x576       50.00  
   720x480       59.94  
   640x480       59.94    59.93  

and likewise in Nvidia control centre shows it even when on standby:

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Does Nvidia GPU send data through HDMI when monitor turned off, (but not disconnected from power)?

Answer 1

On both Windows and Linux I have set up the laptop in mirror with TV.

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Windows 10 (Pro build 2004)

For some reason this is likely OS/driver-dependent, because when I just booted up my Windows 10, and wanted just to play some heavy online HTML5 game, I noticed a massive drop in performance + increased heat, both of which stopped when I disconnected the HDMI cable.

Linux Mint 20 (Cinnamon)

Here I can see no noticeable performance difference when plugged in/out.

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Conclusion

It's likely hardware setup dependant (various TVs / monitors might behave differently), but in my particular case, at least Windows I can confirm sends visuals through HDMI even when TV turned off. How else can we explain the massive drop in performance anyway.