u/DerFelix

I have been trying for hours to get Moonlight to work with VRR on Windows, but it's not working. I will first write about why I think it should be possible and then what I have tried.

Why I think it should work:

• VRR just works when you use Moonlight (same version number) on SteamOS/Bazzite in Gamemode (using gamescope). I can check in my TVs overlay that VRR is turned on and the refresh rate syncs to the reported fps of the game. It is a noticeably smoother experience with VRR turned on vs off.
• VRR even works in Moonlight on Windows as long as I am in the GUI before starting the stream. However as soon as I start the stream the refresh rate just goes to 120 and stays there. (The reported refresh rate in the GUI is about 50 Hz for some reason)
• I have seen conflicting info in random reddit threads saying since this is a video it renders at 120 fps consistently. But I don't think that is true because when I turn on the streaming stats of Moonlight it shows that it's rendering at the exact frame rate it receives from the host. But the refresh rate, as I said, is still at 120 and I can see micro stutters.
• When I inject Lossless Scaling on top of Moonlight VRR works. But this introduces massive latency and is not desirable.

What I have tried:

• All the settings in Moonlight, i.e. vsync on or off, frame pacing on or off, software/hardware decoding, fullscreen, borderless, windowed.
• Lossless scaling (see above), but it's not the desired outcome because of latency.
• Injecting Special K. It shows it is using the correct flip model, but it also shows VRR capable but inactive.
• Frame limiting (see below)
• All sorts of Nvidia settings, obviously Gsync compatible fullscreen and windowed, but also vsync on/off/fast, low latency. I also tried frame limiting in there, interestingly this doesn't seem to do anything, even when set to ridiculously low values. So I think as soon as the stream starts Nvidia thinks Moonlight is not a game anymore or something. I added Moonlight specifically as a Program in Nvidia graphics settings, but it still didn't do anything.

And if you're going to answer: "Just use Linux then". I was doing that before but I have been running into countless problems with HDR and 4K resolution switches on Linux. I want to use my PC as a HTPC and run Plex and other apps that can support HDR video. The only way to get that part to work is to use Windows. And no, HDR is not turned on when launching Moonlight so this has nothing to do with it.

The TV is a Samsung QN90BA (50 inch).

I recently switched to SteamOS from Bazzite (and Windows previously, obviously).

One reason I enjoyed Bazzite over Windows was that VRR just always immediately worked in any game, regardless if the game originally supported it. I switched to SteamOS a few days ago because they improved support for the Xbox Ally X and when I tried it, overall it just seemed sleeker.

I use a 6 in 1 dock from Ugreen to connect the Ally X to my TV and previously on Bazzite I did use VRR with the full capability. I also just tried it with another device, the TV, the cable and the dock are not the problem.

The TV is capable to support VRR at up to 4K120, or 1080p144 even. All I am trying is to get it to work at 1080p120 at least.

Every time I tried it the screen just turns black or sometimes flickers a bit. I spent hours troubleshooting it yesterday and today. Finally I found that if I set it to 1080p100 I can get it to work. Not optimal but it is something.

Is this a common problem? Is there a solution? The reasons I don't want to go back to Bazzite is the iffy controller support, frequent audio problems and on bazzite the connection to the external display sometimes failed for other reasons. On SteamOS the TV is found immediately every time. It just goes to a black screen when VRR is turned on (at 120Hz).