Constant stuttering in VR. I gave up.

[Hiob]

33 minutes ago, speed-of-heat said:

RTSS can also cause issues especially if monitoring those voltages 

Same goes for any kind of monitoring software (hwinfo, hwmonitor, aquasuit etc.) the more queries are pulled the more interrupts are produced. 
I had a wonderful custom build sensor suit in aquasuit running (my second hobby is watercooling) until I noticed how incredible bad that was for fluid game graphics.
Now I tend to religiously reduce processes on my system. Since then I'm basically free from stuttering (unless I run in real performance boundaries).

[MoleUK]

1 hour ago, speed-of-heat said:

RTSS can also cause issues especially if monitoring those voltages 

What trips people up is that afterburner monitors the power and power % by default, causing the problem.

RTSS doesn't, so typically just disabling afterburner but keeping RTSS running is fine. But ideally it's to be avoided, unfortunately DCS doesn't seem to do too well unless an external frame cap of some sort is in place though. But that isn't entirely unusual in modern gaming.

1 hour ago, Hiob said:

Same goes for any kind of monitoring software (hwinfo, hwmonitor, aquasuit etc.) the more queries are pulled the more interrupts are produced. 
I had a wonderful custom build sensor suit in aquasuit running (my second hobby is watercooling) until I noticed how incredible bad that was for fluid game graphics.
Now I tend to religiously reduce processes on my system. Since then I'm basically free from stuttering (unless I run in real performance boundaries).

Yep. The list of 3rd party apps that really conflict with DCS only continues to grow, it seems to be especially sensitive to them. It does make sense given the level of strain it can put on the CPU, GPU and memory all the same time I guess.

Edited April 15 by MoleUK

[diamond26]

@speed-of-heat, @MoleUK I can confirm that NVCP FPS limit works in DCS VR using Link. Tested with QuestPro and Nividia drivers 566.36. Requested 90hz from Qpro and the result was 71 FPS which was the limit in NVCP

[Alexified]

On 4/13/2025 at 11:48 AM, MoleUK said:

Unfortunately there are a LOT of potential causes for VR stutters. It's one of the most frustrating issues DCS has.

When you say the entire scenery, do you mean ONLY the scenery? Are the planes and everything else smooth in movement, but only the scenery jitters, as shown in the video here? If so, I have some suggestions you can try, they have worked to reduce or eliminate terrain stutter/jitter for some users but not all. Let me know.

 

As for more general stutter problems that don't appear the same as shown in the video: roll back nvidia drivers to 566.36 due to recent nvidia issues. Be sure to do a proper DDU process for that rollback.

Make sure mouse polling is at 125hz or less. This issue never entirely went away, and I think might have re-appeared for some users recently.

Make sure CPU core parking is disabled, and potentially you may want to disable low power states in BIOS.

Exclude the DCS install folder and savedgames folder from your antivirus.

Make sure programs that cause issues are either not installed or not running. MSI afterburner, iCue, armory crate, Nvidia app (the new one) and anything that monitors CPU usage can/will all cause issues with DCS. As can any program with overlays. Then there is also DCS specific stuff like tacview, and various mods that even when deleted can leave leftover files in various folders (the Loach AI gunner file in the hooks folder in particular).

If it's more like the terrain jitter shown in the video: Try using an external FPS cap and limit DCS to 71 frames (if running the headset at 72hz), I would suggest either nvidia control panel or RTSS. If that doesn't work, try running keeping that FPS cap and also using nvidia control panel to set DCS to vsync fast and low latency ultra. Let me know if it does anything, you may notice the FPS stats in DCS also start showing you as GPU limited when hitting your frame rate as well after those changes, rather than listing it as CPU render threat limited.

The terrain jitter problem is years old and actually isn't limited to just VR, it's just either a lot more prevalent or a lot more noticeable in VR. Or both. I have 0 experience in game dev or coding, but I assume it's something to do with poor frame pacing or a mismatch between the CPU thread handling terrain rendering and the others, but that's just a guess. But it might explain why external FPS caps seem to help alleviate it for some users, if not all.

Since today, the new TP-Link has been running as a dedicated router, and the latency has dropped significantly.
During the first test run, however, I still had jitter (latency 66ms, gaming 12ms), which suddenly stopped after about 30 seconds and then reappeared after a while.
Well... and then I set the mouse to a polling rate of 125, and BAM, no more jitter. I would never have thought of that.
 

[MoleUK]

28 minutes ago, Alexified said:

Since today, the new TP-Link has been running as a dedicated router, and the latency has dropped significantly.
During the first test run, however, I still had jitter (latency 66ms, gaming 12ms), which suddenly stopped after about 30 seconds and then reappeared after a while.
Well... and then I set the mouse to a polling rate of 125, and BAM, no more jitter. I would never have thought of that.
 

Good to hear something worked. The mouse polling thing is a bit of a DCS'ism that re-appears from time to time, very few other games are affected by it.

[onib89]

3 hours ago, Alexified said:

Since today, the new TP-Link has been running as a dedicated router, and the latency has dropped significantly.
During the first test run, however, I still had jitter (latency 66ms, gaming 12ms), which suddenly stopped after about 30 seconds and then reappeared after a while.
Well... and then I set the mouse to a polling rate of 125, and BAM, no more jitter. I would never have thought of that.
 

What a router has to do with stutters??? 

[Hiob]

4 minutes ago, onib89 said:

What a router has to do with stutters??? 

A lot if you happen to use a wireless HMD like the Meta 3

[Leg2ion]

On 4/13/2025 at 10:48 AM, MoleUK said:

Make sure programs that cause issues are either not installed or not running. MSI afterburner, iCue, armory crate, Nvidia app (the new one)

Was getting exactly what is shown in the video (though 2d so apologies for jumping in) - but only in the Iraq map - so unsure what changes to make if any. Will try the ultra latency and limiting FPS in the NVCP.

One thing I did do was to disable the Nvidia 'Overlay'  in the Nvidia App - that did appear to make things slightly better - though whether a placebo or not remains to be seen. I originally thought it was part of the new DCS/NVidia tie up - until I opened the app up.

[Qcumber]

13 hours ago, Leg2ion said:

Was getting exactly what is shown in the video (though 2d so apologies for jumping in) - but only in the Iraq map - so unsure what changes to make if any. Will try the ultra latency and limiting FPS in the NVCP.

One thing I did do was to disable the Nvidia 'Overlay'  in the Nvidia App - that did appear to make things slightly better - though whether a placebo or not remains to be seen. I originally thought it was part of the new DCS/NVidia tie up - until I opened the app up.

I have been looking at factors which affect VR performance. You can have a relatively stable FPS but still have stutter if your CPU and/or GPU render times are borderline for maintaining the headset refresh rate. For example if you run at 72Hz the max render time is 13.89ms. If your average render time is about 13ms, the min and max times might vary from about 10ms to 15ms. Anything that goes above 13.89ms will result in dropped frames. You can have a significant number of dropped games but without any noticable change in average FPS. This can manifest as microstutter.

If you are technically minded you could try my guide here and see what your render times look like. Compare different tacks, one where you see stutter and one were you don't and see if there is any difference. Or just run a track with XRFrameTools and send me the log and I'll do the rest. 

Edit: scratch that. I forgot you are using a monitor. However some of these principles will still apply. 

 

 

Edited April 17 by Qcumber

[MoleUK]

13 hours ago, Leg2ion said:

Was getting exactly what is shown in the video (though 2d so apologies for jumping in) - but only in the Iraq map - so unsure what changes to make if any. Will try the ultra latency and limiting FPS in the NVCP.

One thing I did do was to disable the Nvidia 'Overlay'  in the Nvidia App - that did appear to make things slightly better - though whether a placebo or not remains to be seen. I originally thought it was part of the new DCS/NVidia tie up - until I opened the app up.

Let me know if capping the FPS does the trick or not, doesn't seem to work for everyone but it's noticeable when it works. Seems to work better when capped under what you can achieve, eg if you're usually hitting 75FPS average try capping it at 70.

Unfortunately any overlays can cause issues with game performance, the new nvidia app is just particularly bad for it atm.

12 hours ago, Qcumber said:

I have been looking at factors which affect VR performance. You can have a relatively stable FPS but still have stutter if your CPU and/or GPU render times are borderline for maintaining the headset refresh rate. For example if you run at 72Hz the max render time is 13.89ms. If your average render time is about 13ms, the min and max times might vary from about 10ms to 15ms. Anything that goes above 13.89ms will result in dropped frames. You can have a significant number of dropped games but without any noticable change in average FPS. This can manifest as microstutter.

If you are technically minded you could try my guide here and see what your render times look like. Compare different tacks, one where you see stutter and one were you don't and see if there is any difference. Or just run a track with XRFrameTools and send me the log and I'll do the rest. 

 

 

He's on flatscreen, the terrain jitter can happen there too as it's a problem with the game engine rather than something VR specific.

Edited April 17 by MoleUK

[Qcumber]

23 minutes ago, MoleUK said:

Let me know if capping the FPS does the trick or not, doesn't seem to work for everyone but it's noticeable when it works. Seems to work better when capped under what you can achieve, eg if you're usually hitting 75FPS average try capping it at 70.

Unfortunately any overlays can cause issues with game performance, the new nvidia app is just particularly bad for it atm.

He's on flatscreen, the terrain jitter can happen there too as it's a problem with the game engine rather than something VR specific.

Even in a flat screen he can still see what his CPU and GPU are doing. I'm not convinced that the stutter is always a game engine issue as such. I have noticed that it tends to appear when CPU and/or GPU render times are close to the max required to maintain refresh rate (in VR anyway). Technically the same would be the case for the refresh rate of a monitor. There are definitely situations in DCS which make this more likely to happen. 

[Hiob]

2 hours ago, Qcumber said:

Even in a flat screen he can still see what his CPU and GPU are doing. I'm not convinced that the stutter is always a game engine issue as such. I have noticed that it tends to appear when CPU and/or GPU render times are close to the max required to maintain refresh rate (in VR anyway). Technically the same would be the case for the refresh rate of a monitor. There are definitely situations in DCS which make this more likely to happen. 

I would argue that (micro-) stuttering, given that the average fps are still high enough, is most likely caused by system latency (aka windows or other 3rd party processes) and not by the game engine. That is why maintaining a sleak system is so importance for edge cases like VR.

On a well maintained System you have at least ~100 processes running, when Windows is whistling La Paloma on idle. These processes are still active when the game runs. Most of them won't do much, but even if only some of them constantly nag for attention and CPU cycles, it can cause latency that manifest in stutters. 

[MoleUK]

4 hours ago, Qcumber said:

Even in a flat screen he can still see what his CPU and GPU are doing. I'm not convinced that the stutter is always a game engine issue as such. I have noticed that it tends to appear when CPU and/or GPU render times are close to the max required to maintain refresh rate (in VR anyway). Technically the same would be the case for the refresh rate of a monitor. There are definitely situations in DCS which make this more likely to happen. 

Could be, but in past testing it can also happen when CPU and GPU load are fairly low. I might end up doing some test runs to reproduce it reliably if I can be bothered, but I am a lazy man.

1 hour ago, Hiob said:

I would argue that (micro-) stuttering, given that the average fps are still high enough, is most likely caused by system latency (aka windows or other 3rd party processes) and not by the game engine. That is why maintaining a sleak system is so importance for edge cases like VR.

On a well maintained System you have at least ~100 processes running, when Windows is whistling La Paloma on idle. These processes are still active when the game runs. Most of them won't do much, but even if only some of them constantly nag for attention and CPU cycles, it can cause latency that manifest in stutters. 

The thing is, I don't think this is microstuttering. It doesn't feel like it anyway, and it presents more like the frames for terrain literally being rendered out of order. They are going back and forward in motion while everything else remains smooth, that to me doesn't point towards it being a stutter or microstutter issue as seen in other games.

The problem is there are a ton of actual stutter issues in DCS as well, which confuses things a bit.

Edited April 17 by MoleUK

[Qcumber]

1 hour ago, Hiob said:

I would argue that (micro-) stuttering, given that the average fps are still high enough, is most likely caused by system latency (aka windows or other 3rd party processes) and not by the game engine. That is why maintaining a sleak system is so importance for edge cases like VR.

On a well maintained System you have at least ~100 processes running, when Windows is whistling La Paloma on idle. These processes are still active when the game runs. Most of them won't do much, but even if only some of them constantly nag for attention and CPU cycles, it can cause latency that manifest in stutters. 

I would agree with you that a lot of stuttering issues are system related. However, even with what appears to be a stable FPS, the rendering time for CPU or GPU can sometimes exceed the maximum time. You can only really see this if you capture every frame. I'm not sure if the DCS overlay does this. I've been looking at some tracks using XRFrametools and trying to create situations where this occurs. It's not an easy task to create this in a stable and reproducible setup. 

[Hiob]

17 minutes ago, Qcumber said:

I would agree with you that a lot of stuttering issues are system related. However, even with what appears to be a stable FPS, the rendering time for CPU or GPU can sometimes exceed the maximum time. You can only really see this if you capture every frame. I'm not sure if the DCS overlay does this. I've been looking at some tracks using XRFrametools and trying to create situations where this occurs. It's not an easy task to create this in a stable and reproducible setup. 

to a degree I'd say. I can only speak for 2D gameplay here, but when not at the limit, the ingame frametime graph is flat as a lake and so is the frametime graph of Afterburner/Riva.

When however there is a spike in the frametime graph - e.g. due to loading a new asset in or whatever or a heavy AI-script running, it corresponds pretty well with what you see on the screen.

Really, hunting down the root cause of "un-fluid" graphics is Sisyphus work, that's why it is so difficult to nail it down AND transfer the results to other systems.

In this special case, with what @MoleUK is reporting it may very well a completely different issue.

[Leg2ion]

On 4/17/2025 at 8:33 AM, MoleUK said:

Let me know if capping the FPS does the trick or not, doesn't seem to work for everyone but it's noticeable when it works. Seems to work better when capped under what you can achieve, eg if you're usually hitting 75FPS average try capping it at 70.

Hi @MoleUK TBH not sure. Things do seem a little better but not entirely 100%. I think it may be fact I am flying over Mosul low level in the Apache - lots of built up areas and straight lines and edges that are possibly amplifying what I am seeing. When I first noticed it - I can only liken it to someone holding me back as if I was trying to run, then letting go - repeatedly though at quick time speed - so 'slow-mo/wading thru mud' then jump forward. 

I don't appear to get the issue in any other map so maybe Iraq/built up area specific.

I capped my FPS to 120, both my monitors are 1920*1080 @120hz - but will start reducing it down to see if there is any noticeable affect/improvement.

Edit. Just spent an hour or so flying around Northern West Germany - no problems whatsoever. Swapped back onto Iraq - slightly different now but still the odd issue - in that as I lift there are a couple of big pauses, then it seems to right itself.

Edited April 18 by Leg2ion
More info.

[CaptSteviej]

I too have suddenly been having problems with VR Stuttering using my Pimax Crystal the last few months. I tried everything in this thread and more to remove this problem. I then ran across this video over at Gamers Nexus and rolled back my Nvidia driver for my 4090 to 566.36 per the recommendation in the video.

My stuttering is almost completely gone and my rig runs very smooth now. It seems that Nvidia has been having drivers issues since December that have only gotten worse. Hope this helps solve your problems

Capt StevieJ