So, 4K @ 120Hz with Linux via HDMI on a TV...

[Waifu4Life]

Of course I learned that this was not a thing after shelling out $800 CAD (including taxes) on an RX 7800 XT. Before retuning this card to Amazon, can anyone point to a working DP to HDMI 2.1 that would correct this (if this is a thing and not a myth)? Finally, some people say that FreeSync won't work with such a solution, why is that?

[Prodigious]

freesync premium might work. so it'd work on a proper monitor. tvs have built in hdcp, so they force hdmi which is ♥♥♥♥ anyway, even if you ran it on windows itd be problematic i think. youre usually getting slower response times anyways on a tv.

[ripper81]

HDMI 2.1 uses it's own VRR technology instead of Freesync or G-Sync. This is part of the HDMI 2.1 specification. Since this part of the specification is proprietary and not documented it is not supportet on linux for any GPU that uses opensource drivers. This means there will be no support for Intel or AMD GPU'S for VRR over HDMI 2.1. If the display has support for Freesync it should be possible to use it instead of HDMI 2.1 VRR. It might be possible to use HDMI 2.1 VRR on linux with an NVIDIA GPU and their proprietary driver.

However support for VRR technologies in general on linux is pretty incomplete and limited because of technical limitations of X.org/X11. In the long run this is about to change because of Wayland. But It will probably take several years since every Waylandcompositor (and Linux desktopenvironment) will have proper support for VRR.

[✠ NightKnight ✠]

Originally posted by Waifu4Life:

Of course I learned that this was not a thing after shelling out $800 CAD (including taxes) on an RX 7800 XT. Before retuning this card to Amazon, can anyone point to a working DP to HDMI 2.1 that would correct this (if this is a thing and not a myth)? Finally, some people say that FreeSync won't work with such a solution, why is that?

I have 4k 120hz , i dont have problems with VRR , playing Bannerlord and some city builders all good. Using real HDMI 2.1 cable for 30$ . (certified). No problems WHAT SO EVER. I am sure its your config. I am using arch btw.

[Waifu4Life]

Originally posted by NightKnight:

I have 4k 120hz , i dont have problems with VRR , playing Bannerlord and some city builders all good. Using real HDMI 2.1 cable for 30$ . (certified). No problems WHAT SO EVER. I am sure its your config. I am using arch btw.:winterbunny2023:

What's your GPU?

Originally posted by ripper81:

HDMI 2.1 uses it's own VRR technology instead of Freesync or G-Sync. This is part of the HDMI 2.1 specification. Since this part of the specification is proprietary and not documented it is not supportet on linux for any GPU that uses opensource drivers. This means there will be no support for Intel or AMD GPU'S for VRR over HDMI 2.1. If the display has support for Freesync it should be possible to use it instead of HDMI 2.1 VRR. It might be possible to use HDMI 2.1 VRR on linux with an NVIDIA GPU and their proprietary driver.

However support for VRR technologies in general on linux is pretty incomplete and limited because of technical limitations of X.org/X11. In the long run this is about to change because of Wayland. But It will probably take several years since every Waylandcompositor (and Linux desktopenvironment) will have proper support for VRR.

Good stuff, thanks.