4K 120hz, HVEC and HDR not working

[StavNat]

In recent months (I believe since the last update, but I can't be certain as I have stints of using and not using this program) I have been unable to get above 60fps streaming working on Xbox Series X.

I am also unable to test whether this occurs in H.264, non-HDR streaming but those toggles don't seem to function any more - whatever I select, the stream claims to be HEVC + HDR.

To Reproduce
Settings on client (matched on host PC)...
Resolution = 3840x2160
FPS = 120
Bitrate = As needed (I usually stream at 250mbps over a gigabit wired connection in-home, have tested this issue at multiple bitrate caps with no apparent effect)

Expected behavior
4K @ 120hz refresh display on 4K @ 120hz TV, with or without HRD support.

Screenshots or Videos
Per attached.

** Logs **
Per screenshot.
The console seems to think it's receiving an ~120fps stream but it LOOKS and FEELS like a 60fps stream.

Guest Information:

• Xbox Model: Xbox Series X
• TV Resolution: (TCL 75C855 using HDMI 2.1) 4K,HDR,120hz,VRR

Host Information

• Operating System: Windows 11
• Host Software: Apollo with virtual monitor
• Monitor Resolutions: Connected monitor 4K @ 240hz, Virtual Monitor 4K @120hz

Additional context
Per attached screenshot, I'm using blue-busters UFO to check smoothness (although it's apparent in gaming too - locking to 60fps provides an identical experience). The site recognizes 120hz refresh so compares 120 and 60 rate UFOs, but both look the same on stream. In fact the 120hz UFO stutters noticeably whereas the 60hz one is consistent, if blurry.

Using other clients on the same display (Mac M4 Mini and Rog Ally X) using Moonlight, the 120hz stream performs as expected and there is a noticeable clarity + smoothness difference between 60hz and 120hz.

[GuiDev1994]

Same here, 60hz works perfectly, but 120hz is struggling my framerate, a lot of stutterings

[GuiDev1994]

Tried everything, nothing works, in all my devices 4k 120hz hdr works but not with this UWP version and Apollo version, maybe we need another update on Apollo, because the Apollo OP had say that the Codec was not ok with xbox clients and AMD Graphics Cards

[StavNat]

I thought it might have had something to do with Apollo too, though as above all my other moonlight clients work as expected. There has been an Apollo update since this issue began for me but it hasn't resolved.

If anyone has similar experiences using NVGFE or Sunshine, would love to hear it. Last time I tried to swap between them / run multiple streamer services, I created a lot of problems for myself and I only have one client!

[GuiDev1994]

Did you already changed the Apollo version to 2024? In 2024 Xbox client was working perfectly in 4k 120hz. Maybe it's a beggining. I will try too. Is not a problem for me to change the version, it will put some lattency but it's ok.

[Wordsmith9091]

I wonder if this has something to do with the Intra Refresh mode added to Apollo a while back, and then the later update to HDR streaming here.

[GuiDev1994]

I don't think that is relationed to the Infra Refresh, because it is an option directly relationed to the Nvidia GPU's. I own an AMD GPU, and i have the same problem.
I think is more related to the HDR, because the own Apollo developer said that they messed with the decoders on Xbox Client and all the things goes wrong, with a lot of arctifacts too.
Unfortunally, the active developer of this client doesn't answer any issue, maybe we could help too.

[Wordsmith9091]

Yeah. Don't get me wrong, I'm grateful for the work the developer(s) put in, but the relative radio silence on the issues and discussions forums sort of defeats the point of having those spaces at all.

[mufaaf]

It seems 120Hz is the issue here, and not 4K or HDR.

I just tried 1440p/120fps and I get a lot of stuttering, where as it works flawlessly on my Android tablet at the same resolution and frame rate.

It's a shame that 120fps doesn't work properly. 60fps doesn't seem to have any problem and works smoothly. I hope there is a solution to this somewhere. I have tried capping my frames to 117 and 119.88 but nothing. I don't think that makes any sort of difference at all.

[gustavom95]

I can confirm the same. 4K and HDR work properly on the client, and it believes it's 120fps, but blurbusters shows no difference between 120 and 60. Other clients I've tried (Android) do show a difference.

I am running the latest version of Apollo as the server. Has anyone had success with a different version, or perhaps Sunshine?

Game Mode info on my Samsung TV also confirms it as 60fps, though the stream itself says 120. Included a photo of stream info and logs.

[StavNat]

I've had cause to reformat my computer this week so tried by reverting to versions of Apollo from the start of the year. I tried a few versions betweenbut none seem to make a difference - it appears to be client-side for me. I'm going to try vanilla Sunshine next.

[Wordsmith9091]

I'm definitely curious about the resilts you get. I've wondered if it may have something to do with the Intra Refresh Apollo automatically uses for the Xbox client, since I'm not sure whether it's still needed, but I doubt that's actually the issue. It doesn't cause problems on other clients even if on universally.

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On Sat, Jun 21, 2025, 9:22 PM StavNat ***@***.***> wrote: *StavNat* left a comment (TheElixZammuto/moonlight-xbox#197) <#197 (comment)> I've had cause to reformat my computer this week so tried by reverting to versions of Apollo from the start of the year. I tried a few versions betweenbut none seem to make a difference - it *appears* to be client-side for me. I'm going to try vanilla Sunshine next. — Reply to this email directly, view it on GitHub <#197 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A5V7ARIHZHVB33WZLXOQTXL3EYAO3AVCNFSM6AAAAAB6W5K622VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSOJTHA2TOMZZGY> . You are receiving this because you commented.Message ID: ***@***.***>

[GuiDev1994]

The problem is with the Xbox Client. Maybe the developer only tested with 4k 60hz non hdr.
Apollo Server is working perfectly with the last version.

[mufaaf]

Yeah, the problem is with the Xbox client, than Apollo or the TV.

I just tested the refresh rate on my LG C9 and it correctly registers 120hz.

I wonder if the problem lies in it compensating for TVs and shifting the refresh rate to 119.88 that’s causing the issue? It does for 60fps content, where the streamed refresh rate is 59.94hz. I don’t think it would cause any issue from my experience but it’s an idea.

[GuiDev1994]

The problem is with the decoder.
ClassicOldSon already said that the decoder is not working well with xbox clients on the last version.
The decoder needs to follow the encoding transmission, if you're streaming in 120fps, the decoder needs to decode in 120fps too.
I guess that they improve the hdr and bitrate, but fixed to 60fps the transmission.
In this last version, we have a lot of arctifacts too, very strange.
I bought the xbox series s only for Moonlight usage, 4k 120hz hdr. Sad.

[Wordsmith9091]

So did I. I'm very grateful to the developers of this project and all the related ones for the work they've done, but I really do wish they would participate in these discussions to let us know if issues like this are on their radar and might be addressed. **

…

On Sat, Jun 21, 2025, 9:53 PM guido2708 ***@***.***> wrote: *guido2708* left a comment (TheElixZammuto/moonlight-xbox#197) <#197 (comment)> The problem is with the decoder. ClassicOldSon already said that the decoder is not working well with xbox clients on the last version. The decoder needs to follow the encoding transmission, if you're streaming in 120fps, the decoder needs to decode in 120fps too. I guess that they improve the hdr and bitrate, but fixed to 60fps the transmission. In this last version, we have a lot of arctifacts too, very strange. I bought the xbox series s only for Moonlight usage, 4k 120hz hdr. Sad. — Reply to this email directly, view it on GitHub <#197 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A5V7ARKRBMN5NLJBQLWJTUL3EYEBBAVCNFSM6AAAAAB6W5K622VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSOJTHA3TCNZTGQ> . You are receiving this because you commented.Message ID: ***@***.***>