With the launch of Fedora 40, there is an experimental option within Gnome to allow variable refresh rate and potentially save battery life on laptops!
I was excited to hear this, but when attempting to implement, it seems on my 11th gen intel Framework 13, it doesn’t apply the settings update. Below are 2 links that effecitvely say the same thing:
run gsettings set org.gnome.mutter experimental-features "['variable-refresh-rate']" in terminal, log out/reboot and log back in and the option should now be available in your display settings.
Instead, I lost my fractional scaling option and still don’t have variable refresh rate. My brother is also running Fedora 40 and updated his laptop with the terminal command. He is NOT on a Framework laptop and his does work. I don’t remember his specs but if it’s relevent I’ll ask. Does anyone have a similar experience so far or is this just isolated to me?
The panel in the FW13 supports Panel Self Refresh tho (PSR) which is specifically targeted at updated areas (sorta like xdamage) AFAIK any recent kernel (6.6 onwards IIRC) should support this as it’s low level in the amdgpu driver stack. There were some issues at F39 with this but it got smoothed out in that series kernel. This works without any user interactions.
At least for the AMD FW13 panel you can also set the refresh to 48hz if you want manually, but I haven’t noticed any appreciable power gains running with it vs 60hz
VRR and PSR are not the same. I have no idea of the sate of PSR in the intel drm stack . But it’s unrelated to VRR in any-case. As the previous poster mentioned VRR support isn’t implemented or exposed on the 13 Inch panels. The panel in the AMD FW13 does IIRC support PSR(although I may be mistaken) - which will ‘just work’ on any recent kernel. The same panel also exposes a stable 48hz set of modes in addition to it’s 60hz ones in it’s EDID - which means you can just select this in the display settings. As for VRR support ; this has been in kwayland/plasma for a while, and it’s been in mutter(gnome) for a bit and is in f39 (but not exposed in the GUI settings) - the version of gnome in fc40 makes this exposed to the user. But once again this needs to be reported by the outputs capabilities; and it’s complicated for external displays as often VRR isn’t available on all ports of all monitors (often toggled as ‘game mode’ in the monitor settings) and also relies on whatever Displayport to HDMI conversion chip/pathway is being used to work reliably