Micro-stuttering issue in regards to DesktopPlus - SteamVR relationships.

[Stepone11]

Hi! This is my third ''ticket'', so thanks for your answers. There are always helpful.
This time I wanted to ask you if there's a way to change steamVR settings (maybe something in their config file )
that can help with micro-stutters. (I doubt DesktopPlus settings would affect this issue )
Here's the whole scenerio -
I'm using DesktopPlus in SBS mode to stream flat games in my Quest 3. (reshade is used for depth but it doesn't matter in this case)
Quality of image as always is top-notch. Very sharp and detailed.
The only issue is on my flat monitor - there's no micro-stutters at all (99.9% of time anyway)
But every 5-10 second in my headset there'll be micro-stutters lasting 1-3 second then it's ok for another 5-10 second- super smooth and all.
Things that i do to somewaht improve it are :

1. My physical monitor is set to 60hz.
2. Surely in this case my hdm is set to 120 and therefore in steamVR it's the same. 120hz mode. ( 2 to 1 ratio basically )
3. It also depends on a game (for some reason). Some games will perfectly work with almost no micro-stutters ( in a headset, there'no micro-stutters on flat setup ever)
4. For those stubborn games where stutters do happen every 5-10 seconds. The best thing that at least makes it a bit more playable is setting nvidia Vsync - to ON or adaptive. (in game vsync is off - it's never a good option in my experience )
5. I do use RTSS tool to lock my fps to my physical monitor which is 60hz. - that's a really important step and with it it's almost always smoother in a headset. We don't ever do it for VR games or mods since Vsync is handled by other methods. but in this case it's a crucial step. without it it's a lot worse in a headset.
   So, SteamVR is set to 120, fps is locked at 60. and Vsync is on via driver's settings.
   On paper everything is good, right? Well on my flat monitor it is, i do use all of the above for my flat setup as well - RTSS to lock fps and Vsync via Nvidia panel - and flat games are always buttery smooth.

Where do i go from here to get rid of those micro-stutters in a headset i - that i don't know -
I've also disabled steam's motion smoothing feature via config file - just in case. it didn't do anything though.
Also my gpu usage is always below 90% so my setup as far as hadware can't be an issue. I'm not pushing my games too hard. there's always headroom.

It seems the issue is something within SteamVR because once again blurry Virtual Desktop by Meta has no micro-stutters in the same scererio when streaming pc desktop :D it's very blurry though hence I use DesktopPlus for streaming flat games.

Just to add to the whole the refresh rate and fps ratio thing - I did also try setting my monitor to 72hz and my headset to 72. In that case i used 72fps as a lock in RTSS tool. There was improvement on micro-stutters..
There used to be throttling behavior setting in steamVR , i think it could've be a solution maybe,. but it was removed a while back i think., i can't see this option anymore.

Hopefully it wasn't too long of a description. I wanted to be very specific.
Thanks in advance!

[elvissteinjr]

It's hard to say, really.
Number one resource hog enabled by default would be SteamVR Home, but I doubt you have that running in the background when doing this.
Otherwise SteamVR has been decent in terms of smoothness for me over the years. For most of that time that was on a GTX 1070 actually, so raw GPU power isn't even much of a factor as long as it's not bogged down entirely.
But I'm also still a Valve Index user, so wired and native headset. For Quest there's always at least one guy complaining about something broken... and even I don't doubt it. But I wouldn't have any experience to share there I suppose.

Do these micro-stutters appear as stutters for the whole HMD view or just for the overlay capture? Does the capture FPS fluctuate when it happens ("Performance" -> "[x] Show FPS in Floating UI")?
Does the game where this happens use the mouse cursor? Cursor updates are handled independently of display updates and may exceed the refresh rate greatly. In that case hiding the cursor or limiting the overlay updates may help. Though it's only on movement however, so hiding is probably not useful if you actually need the cursor.
For Desktop Duplication I recommend playing the games in exclusive fullscreen if available. Disabling fullscreen optimizations may also help, though the main effect is unconstrained frame rate captures (so you could capture 120 fps even when running on a 60 Hz desktop display).
I'm not entirely sure of the effects of adaptive vsync here. From gut feeling it might be better to just have a plain frame limiter on instead, but then it's still a question of frame pacing. Desktop+ does capture frames and send them to SteamVR as soon as possible (unless a limiter is active of course), so if the stutter comes from multiple frames coming in before a VR frame actually gets rendered... but that sounds unlikely in a 60 Hz capture.

Something that shouldn't be necessary but you could also try is SteamVR-VoidScene. This is a small tool designed to lower the GPU overhead for overlay use like this.
I don't believe that tool is necessary to use with recent GPUs, however. I'll just leave it here as an option.

There used to be throttling behavior setting in steamVR , i think it could've be a solution maybe,. but it was removed a while back i think., i can't see this option anymore.

Pretty sure throttling options are still there in the video settings. At least per-game, next to the resolution settings. Those don't apply to overlay applications, however. And some other related settings may only display for SteamVR-native HMDs iirc (things like motion smoothing that are never used in those cases).

[Stepone11]

hey, thanks for the reply!

1. yes i have steamvr home disabled.

2. i'm also connected to pc via cable. so i'm also wired. my default runtime for openXR is oculus runtime. but i don't think it matters.
   and it wouldn't explain why stutters aren't happening all the time i guess.

3. ''Do these micro-stutters appear as stutters for the whole HMD view or just for the overlay capture?'' i'm afraid i didn't get that question.
   i'm lost in terminology. Stutters don't appear on flat setup and frametime is flat (msi afterburner monitors my flat setup performance in this case) and no fps drops ever while at the same time in the headset there're jitters.
   but yes, i should probably turn on ''Show FPS in Floating UI'' option. because i didn't use it, but i guess it'd be helpful to see what happens there.

4. mouse cursor isn't an issue. I've excluded that possibilty it a while back.

5. i'm using fullscreen usually yes. and checked disable fullscreen optimization too. it didn't do anything in my situation though.

6. for some reason without Vsync on - it's even worse. noticeably worse. But also depends on a game. there were a few instances where no vsync but fps capped - was the best solution. i always have to go and check all combinations before i decide.

later on today I'll try-

1. Setting steamVR as native runtime for openXR, though i doubt it will help.
2. turning on ''show fps''option for desktopplus and see what's going on there during micro-stutters.
3. try not to use any other overlay like Msi afterburner/RTSS. and just use fps cap via nvidia panel.... just in case. little hope but worth a try.

Will let you know if something helps.