Hunting for the stutter-free VR experience.

[Panzerlang]

Hours...HOURS! 13900k, 4090, 64GB RAM, game on SSD (not C drive).

In-game graphics settings make zero difference. Ditto resolution. Both, max or minimum, same stutter jerking. Quadviews makes a difference but it's not the fundamental issue. Other things tested:

Windows Defender, DCS and Saved Games excluded. No difference.
Windows Power Service disabled. No difference.
Mouse Polling Rate set to 500hz. No difference.
Combos of resolution set in the headset or in the game. No difference.
72hz Refresh Rate. Image high-frequency flicker, no difference otherwise.
Smoothing on (Pimax Crystal). Stutter worse.
NVidia CP, pre-rendered frames. 4 = more stutter, 1 is best.
Hyperthreading disabled (Process Lasso). No difference.
Quadviews Turbo Off. No difference.
All E-Cores off (Process Lasso). No difference.

Then I started messing with the P-Cores. Fortunately this can be done while the game is running. Pause game, alt-tab to Process Lasso, change settings. 

DCS seems to have a thing for the number of P-Cores. With only two enabled, lots of stutter. With four enabled, the least amount of stutter so far. ALMOST smooth. Up it to six and eight cores, the stutter becomes worse. Four active P-Cores seems to be as good as it gets and you really have to fly low and look sideways and concentrate to see the trees infrequently stutter. I'm almost sure that the stutter becomes constantly timed too, like one micro-jerk per two seconds but it's not reliably reproducible.

My conclusion is that DCS MT has issues with the number of P-Cores it uses. Fking around with that sht absolutely affects the graphical performance.

FWIW.

Oh, the first and last P-Cores, disabling individually and together, no difference.

Edited December 7, 2024 by Panzerlang

[sleighzy]

Drop your "C:\Users\username\Saved Games\DCS\Logs\dcs.log" file here (might just be a text document named "dcs" if your Windows is hiding file extensions) after loading into a mission.

[Panzerlang]

1 hour ago, sleighzy said:

Drop your "C:\Users\username\Saved Games\DCS\Logs\dcs.log" file here (might just be a text document named "dcs" if your Windows is hiding file extensions) after loading into a mission.

Done.

I removed the Saved Games folder from the C drive and copied it into the same location as the game (D drive). I think DCS no longer sees it as there's nothing in the log after I switched locations. I saw in a video that somebody had it on a different drive but I guess it's not as simple as just copy & pasting it over.

 

dcs.log

Edited December 7, 2024 by Panzerlang

[Panzerlang]

Looks like it was saving into the one on the desktop.

dcs.log

[The_Nephilim]

looking at your logs I would suggest checking your Affinity in DCS .. change your Pagefile to at least 32768MB and your VR Headset what Hz rate do you run and what are your FPS in a MP Mission?

 

Also do you use Unofficial Mods?? IF so try and disable and run slow repair and cleanup.. maybe check your settings in DCS I know you said it had no effect if so then something else is amiss perhaps the mods..

Edited December 7, 2024 by The_Nephilim

[Panzerlang]

1 hour ago, The_Nephilim said:

looking at your logs I would suggest checking your Affinity in DCS .. change your Pagefile to at least 32768MB and your VR Headset what Hz rate do you run and what are your FPS in a MP Mission?

 

Also do you use Unofficial Mods?? IF so try and disable and run slow repair and cleanup.. maybe check your settings in DCS I know you said it had no effect if so then something else is amiss perhaps the mods..

Zero mods. Headset is at 90hz. I tried 72hz but it produces a flickering image. I haven't done MP much and won't until I'm properly 'trained'.

FPS...no figure for that, can only say I see zero issues there.

Affinity...isn't that what Process Lasso handles?

[lefuneste01]

I'm in the same quest...As a lot f people, I have stuttering since a long time, but I spent some time and discover they  are mostly created by spikes driving to issueq for Varjo motion smoothing. 

Example here : without motion smooting, game capped at 45 fps, some spikes of few ms. No smart smoothig and not 90 fps => not a fluid display in VR, so I have stuttering but this is normal !

Then the same with motion smooting => every spikes is amplified by motion smoothing, this create a mess and drive to 22 fps !

As you I did a lot of test without finding any conclusion, except preload radius seems amplifying the spikes. Currently I set it up to minimum and I also set "lod" option to 0.2...This is improving but not solving spikes issues. I'll try to map to 4 cores only.

This track (AH64) is showing how you can have those "spikes" even if your rig is producing rougly 60 fps for the scene...
https://www.mediafire.com/file/n2m9jrx80bhrr11/M.trk/file

I wonder if some can reproduce the spikes I have.

Edited December 7, 2024 by lefuneste01

[sleighzy]

6 hours ago, Panzerlang said:

Done.

I removed the Saved Games folder from the C drive and copied it into the same location as the game (D drive). I think DCS no longer sees it as there's nothing in the log after I switched locations. I saw in a video that somebody had it on a different drive but I guess it's not as simple as just copy & pasting it over.

 

dcs.log 83.21 kB · 3 downloads

No, you shouldn't move your Saved Games folder by just copy/cut'n'paste. This will break your profile and other things as it is a system folder. Will also mean DCS may have issues if it attempts to load, e.g. settings/config or save data to that location. You should change the location using the correct process of right clicking on the folder, going to the Location tab, and then clicking move.

[The_Nephilim]

2 hours ago, Panzerlang said:

Zero mods. Headset is at 90hz. I tried 72hz but it produces a flickering image. I haven't done MP much and won't until I'm properly 'trained'.

FPS...no figure for that, can only say I see zero issues there.

Affinity...isn't that what Process Lasso handles?

OK ON mods      if you see flickering @72hz you have very sensetive eyes I dont even see it at 60hz anymore.. well it is important as with VR if you cannot maintain the hz rate or above you get stutter.. I am betting you are not mainataining more then 90FPS in VR..yes well the Windoiws can handle affinity as well but since you are using PL you log is saying alot of cores are diabled so just a friendly remoinder to check and see what you set the affinity at..

 

2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 0 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 2 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 4 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 6 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 8 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 9 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 10 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 11 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 12 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 13 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 14 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 15 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 16 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 17 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 18 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 19 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 20 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 21 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 22 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 23 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 24 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 25 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 26 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 27 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 28 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 29 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 30 is not available for this process
2024-12-07 02:53:37.606 WARNING EDCORE (Main): logical core 31 is not available for this process
2024-12-07 02:53:37.609 INFO    EDCORE (Main): CPU: 13th Gen Intel(R) Core(TM) i9-13900K [1x L3 caches

 

 

 

 

 

 

Edited December 7, 2024 by The_Nephilim

[MarkyMarkUK]

I had similar issues and only recently found a way forward in the last few days @Panzerlang. I have same setup i9 13900k, 4090, 64GB RAM, game on SSD (not C drive). I tried all the things you listed. I have good 90FPS but the frame rate spiked all the time and game was jerky especially near ground. I did find using the VR graphics setting in DCS made it better but of course, it looked like I was playing on a N64  

This is how I got it to work on HIGH Quality DCS settings:

Forget cores and process lasso etc.

Set NVidia to all default and set Power Management Mode to Prefer Maximum Performance

Set Pimax software to all default

I set my Pimax crystal light to Pimax OpenXR (no SteamVR)

90Hz (not Labs)

Set Render Quality to Low

turn off Smart Smoothing

Run game from Pimax Games tab (Games dropdown selector set to 'DCS World Steam Edition' see pic 1 - Click Start button.

In DCS Graphics screen, use the HIGH settings tab and Quadviews on (I now don't use this and it's still very playable for me)

DLSS on set to Quality

I CAN NOW PLAY DCS AND STOP CONSIDERING UNINSTALLING IT AND GETTING IN TO WAR THUNDER

Setting the Render Quality to Low in Pimax software solved the frame time spikes for me and made the game non-jerky. It's only DCS that I need to do this, all my other games are on Medium or High.

War Thunder still looks better, DCS will look not quite as sharp but still VERY playable, in my opinion. I never had frame time issues with PICO 4 and Virtual Desktop by the way.

 

FYI, I'm annoyed that I have a higher resolution VR headset (upgraded from PICO 4) that I have to turn down for DCS only.

 

Edited December 7, 2024 by MarkyMarkUK

[Panzerlang]

I can confirm that there is indeed a 'tick rate' to the stutter, which can be seen by flying over empty ground (no trees or other objects to disrupt it). The stutter/jerk happens approx once every 1.5 or 2 seconds. I don't know what kind of clue that provides but it is a clue.

If, as I suspect, it's caused by ED's multi-threading code there's not much (if anything) we can do to totally eliminate it. I've got it to a point where everything coming at me through the front of the cockpit is perfectly smooth but I can see the slight stutter of the canopy-frame against the ground (low or high altitude) as I roll. Looking sideways, very obvious but nowhere near as bad as before I restricted the game to four P-cores. I also removed use of those four cores from other main processes (headset exe and a couple of other guesses).

[Panzerlang]

1 hour ago, sleighzy said:

No, you shouldn't move your Saved Games folder by just copy/cut'n'paste. This will break your profile and other things as it is a system folder. Will also mean DCS may have issues if it attempts to load, e.g. settings/config or save data to that location. You should change the location using the correct process of right clicking on the folder, going to the Location tab, and then clicking move.

There is no Location Tab in the saved games properties window and it appears to be a widely reported missing function in W11.

[Phantom711]

vor 5 Stunden schrieb Panzerlang:

FPS...no figure for that, can only say I see zero issues there.

Well…the whole discussion is kinda pointless without looking at the FPS. And like others have pointed out, it is rather unlikely that you can manage to have 90FPS near to the ground. And if you don‘t match the HMDs refresh rate (90Hz->90FPS), you will have stutters…more or less.

[Glide]

3 minutes ago, Phantom711 said:

And if you don‘t match the HMDs refresh rate (90Hz->90FPS), you will have stutters…more or less.

Stutters is not quite correct.  You get "old" frames that are slightly out of sync, so you get some double vision happening.  It's easy to see on the runway lights as you rush past them. 

Yes, there is something strange going on, but I'm not convinced it's CPU core related.  I see clearly repetitive behaviour where the CPU frame times are all 5ms, then they jump up to 10ms, then 15ms, then it flushed back to 5ms.  There's a timing issue in there somewhere.

[lefuneste01]

3 hours ago, Phantom711 said:

Well…the whole discussion is kinda pointless without looking at the FPS. And like others have pointed out, it is rather unlikely that you can manage to have 90FPS near to the ground. And if you don‘t match the HMDs refresh rate (90Hz->90FPS), you will have stutters…more or less.

The issue is not fps, as we can use motion smoothing or any similar feature dependind of VR HMD to get fluid experience.

 The issue is the spikes. Why do we have for few ms spikes with fps halfed or worse ?

[Maddaawg]

7 hours ago, Panzerlang said:

There is no Location Tab in the saved games properties window and it appears to be a widely reported missing function in W11.

My Win11 does, under C:\Users\name\ right click on saved games, select properties and then location and move. You may have issues if you just moved it.

[WipeUout]

Had this issue as well and resolved it by re-installing a debloated win11.  Then using process lasso, set any active process not related to DCS or PimaxPlay assigned "below normal" or normal priority and running on e-cores threads only.   DCS and pi_server on high priority and p-core threads only, pimaxclient on high but e-cores threads only.

There might be some different results depending on your CPU but this works fine with my 13900k, buttery smooth experience.  I do have stutters here and there but mainly when switching from external view to in-cockpit and vice-versa.

Some nasty windows software can cause lots of problem like OneDrive, MSI Center or anything that can run in the background.  Monitoring active processes within process lasso while DCS running gives you lots of clues on what is eating CPU cycles. 

Edited December 8, 2024 by WipeUout
Typo

[sleighzy]

8 hours ago, Panzerlang said:

There is no Location Tab in the saved games properties window and it appears to be a widely reported missing function in W11.

It's there on mine. See also this guide: https://www.elevenforum.com/t/move-or-restore-default-location-of-saved-games-folder-in-windows-11.8717/ Like I said, moving the way you have can break this and your profile.

You can try move it back and repeat, but it is potentially broken and you'll need to reference a guide for restoring your profile. There are steps on that guide as well for restoring the Saved Games location so could try that as well to unbreak it.

Edited December 7, 2024 by sleighzy

[Panzerlang]

9 hours ago, Phantom711 said:

Well…the whole discussion is kinda pointless without looking at the FPS. And like others have pointed out, it is rather unlikely that you can manage to have 90FPS near to the ground. And if you don‘t match the HMDs refresh rate (90Hz->90FPS), you will have stutters…more or less.

I tried the setting in Pimax Play to limit FPS to 45, it made the stutter worse. I've also previously played with the Target FPS slider in the game settings and that made things worse too.
As mentioned above, it's not an FPS issue, I see zero ghosting. And I've tried potato graphics settings, looks like vaseline but the stutter is still there. The weird thing is I currently have the graphics settings through the roof (I was trying to bring the game to its knees) and apart from the micro-stutter it runs perfectly. Pimax Play render at 0.5, DCS Pixel Density at 1.5. I should be seeing ghosting at least but there's none.

Re Saved Games, I think you're right Sleighzy, there is no longer a log file in it so I guess I broke something. 

Edited December 7, 2024 by Panzerlang

[sleighzy]

1 hour ago, Panzerlang said:

Re Saved Games, I think you're right Sleighzy, there is no longer a log file in it so I guess I broke something. 

Might be worthwhile checking the datetime stamp on the Saved Games\DCS\Config\options.lua file as well. DCS will read and write your settings to that file so if it can't locate it then some of the settings you're making in game may not be maintained and hence give you false results.

[Panzerlang]

53 minutes ago, sleighzy said:

Might be worthwhile checking the datetime stamp on the Saved Games\DCS\Config\options.lua file as well. DCS will read and write your settings to that file so if it can't locate it then some of the settings you're making in game may not be maintained and hence give you false results.

It's seeing graphics settings ok. I tried Pimax Play render and game's Pixel Density at max together, computer said "NO!". Lol. However, I've established that the image quality is superior with max Pimax and min PD. It's also the smoothest regarding stuttering. I also excluded every other active process from using the four P-cores, except those that Process Lasso advised not to. NVidia Overlay is off. I've got DCS running as lean as possible, bar SimHaptics and DC-Realistic (they both default to using the same cores I set for DCS, so I'm assuming the way they work is they're seen by DCS as a native component). I'm going to test with both of those disabled next.

[Panzerlang]

Yeah, options.lua last datestamp is from yesterday. I broke stuff. Any idea how I'd fix that? I already ran DCS repair prior to the last test missions.

Edited December 8, 2024 by Panzerlang

[sleighzy]

1 hour ago, Panzerlang said:

Yeah, options.lua last datestamp is from yesterday. I broke stuff. Any idea how I'd fix that? I already ran DCS repair prior to the last test missions.

I haven’t run this script but if you go to Option 3 of that link I posted previously it has steps a batch script (and location to zip file) to recreate your Saved Games folder. You should then be able to copy the DCS folder from that other Saved Games location you have and paste it into that one so you still have your DCS config and control bindings etc. 

[Panzerlang]

18 minutes ago, sleighzy said:

I haven’t run this script but if you go to Option 3 of that link I posted previously it has steps a batch script (and location to zip file) to recreate your Saved Games folder. You should then be able to copy the DCS folder from that other Saved Games location you have and paste it into that one so you still have your DCS config and control bindings etc. 

That did it, thanks man.

Ha, the location tab is there now too.

Edited December 8, 2024 by Panzerlang

[lefuneste01]

12 hours ago, WipeUout said:

Had this issue as well and resolved it by re-installing a debloated win11.  Then using process lasso, set any active process not related to DCS or PimaxPlay assigned "below normal" or normal priority and running on e-cores threads only.   DCS and pi_server on high priority and p-core threads only, pimaxclient on high but e-cores threads only.

There might be some different results depending on your CPU but thid works fine with my 13900k, buttery smooth experience.  I do have stutters here and there but mainly when switching from external vire to in-cockpit and vice-versa.

Some nasty windows software can cause lots of problem like OneDrive, MSI Center or anything that can run in the background.  Monitoring active processes within process lasso while DCS running gives you lots of clues on what is eating CPU cycles. 

I do not believe the latency issues you can see in my tracks are created by external processes because they occures always at the same place when replaying the track. So this is really an issue in the game, not outside it.

Edited December 8, 2024 by lefuneste01