I recently made a post about my FreeSync certified monitor not supporting VRR over HDMI. I thought that there was VRR support over HDMI even for versions below 2.1 spec. Am I mistaken in my assumption¿? Has the HDMI forum prevented the implementation of FreeSync in the open source drivers¿?
Obligatory removed the HDMI forum and the HDMI spec.
The Steam Deck only does VRR over Displayport. Valve has their own engineers working on every part of the software stack. It’s their own hardware and their dock. With all that, Valve still can’t get VRR over HDMI to work.
removed the HDMI forum.
Actually it works fine on Steam Deck. It uses VRR over DP to the dock, which then translates it to HDMI with VRR. The dock has proprietary firmware to do this.
Intel and Nvidia hardware with open source kernel drivers also do a similar trick where the HDMI part is in a firmware blob. Only AMD does not work with HDMI VRR.
Source? So it can do 4k, 120hz+ VRR? I have found comments and change logs, but I’m not sure it fixes the HDMI 2.1 issue. Which would be 4k+ @ 120hz+ with VRR.
NM I found what I was looking for.
https://overkill.wtf/steamos-3-5-5-brings-just-so-much-stuff-including-vrr-for-steam-deck-dock/
Looks like it just gets VRR working, generally. Unfortunately not some kind of 2.1 workaround.
It would allow them to do HDMI FRL also, which is probably what you mean when you say HDMI 2.1. AMD cards also do HDMI FRL I thought. FRL is what allows things like 4k120Hz (higher bandwidth modes). The VRR that the Dock does is the VRR standardized with 2.1, which is why it works on TVs and devices that do not support freesync (see: LG TVs).
Anyway, the Dock doesn’t have a fast enough HDMI converter to do that. It’s not a licensing issue. Next gen Deck/Dock will probably do it.