White horizontal stripe across screen while using link

[Panzer_mk2]

Headset seems to work fine stand-alone.  I use the headset with IRacing, and often (not always) get a translucent horizontal stripe across the screen after about 15 minutes or so.  It doesn't feel like the headset is overheating.  This doesn't show up on the screen mirror on PC, or if I "mirror" with the debug tool.  Is this likely a failing display or is there somewhere else I should look?

[benji94]

Hi anpeaco....I think you are the first to report that the numslice fix isn't working.  That is very interesting.  Its these types of situations that often lead to more answers.  I don't have time right at the moment but later on I'll post a couple of suggestions for you to try.  Hang in there!

[starkiller212]

Adding my +1 as a reply to your answer here, which is the real solution, so that future visitors can hopefully find your post more easily. Thanks so much!

[benji94]

Hi anpeaco....I had intended to reply last night but it just got too late.

I'm not familiar with DCS World but upon looking it up I find that it is a combat flight simulator game.  So I put it in the same category as MS Flight Sim and the other simulator games that seem to have a higher incidence of the problem occurring (Dirt Rally, iRacing, and other racing sims).  These simulator games are fast moving and have a LOT going on with respect to environment maps, textures, shadows, and modeling than your typical single shooter games.  This means they can require a LOT more VRAM (GPU memory).  You have a 3080ti which has, I believe, 12 GB of VRAM available.  You would think that would be plenty but maybe not depending on what else you might have running on your system when playing the game.  For instance, a 4K HDR monitor requires a whole lot of VRAM.

Here is a link to a thread on the DCS Forums with players discussing the problem of the 3080ti VRAM being over saturated:

3080Ti possibly full vram ? - Virtual Reality - ED Forums (dcs.world)

A lot of possibilities mentioned in that thread and a lot of discussion about decreasing textures and shadows insure VRAM isn't saturated.  

So that's an area to start for sure.  However, from your post it appears that something triggered the issue.  Meaning all was fine and then suddenly one day it wasn't.  So the obvious question is "what changed?"  Was there any updates?...Nvidia graphics?  Windows?  Game update?....etc.?

If not as far as you can tell then a couple other possibilities is that it could be an overheating issue.  If it starts slowly and gets worse over time it might be your GPU VRAM is becoming too warm and the GPU begins to throttle itself back which then could be causing artifacts.  Overclocking of the GPU could also be a culprit if you've done that.  The worst case scenario is that your VRAM is starting to fail.  Unfortunately it happens.  

Here is a link to an article on how to increase your VRAM allocation:

How to Increase Dedicated Video RAM (VRAM) in Windows 10 and 11 (makeuseof.com)

The fact that you are still seeing the problem irrespective of the number of encoder slices you set in the registry (per Pokebert) hints that the problem you are having isn't quite the same as everyone else because changing the 'numslices' attribute has, as far as the reporting to this thread, been a universal fix.  So it is likely it is some other issue.

You could also try the following to reduce the workload on your GPU's VRAM:

In game:  reduce anything that requires more complex textures and shadows

In the Oculus Debug Tool (be sure to 'run as administrator before changing ODT settings):  set pixels per display override to '0'; 

FOV tangent multiplier:  set horizontal to ..9 and vertical to .8;  This will reduce the number of pixels that need to be rendered on the outside of the display by 30%.  Note that this needs to be re-set every time before you fire up Oculus.

Set the Encode resolution width to 3664 (default for the Quest 2...not sure what it would be for the Pro but if different just set it to '0' to invoke the default.

Set the Encode bitrate to '0' (default...150 mbps (I believe it still is for the Quest 2)

The above settings should help to reduce the GPU's rendering load

Nvidia control panel:  Set Texture filtering - Quality to "Quality" (instead of High Quality)

And finally the Oculus PC app....for whatever framerate you have set (90, 80, or 72) set the resolution slider to default ('0').  If you are running 120 try 90 (or even 80) for testing to see if you can get the problem resolved.  If it goes away you can then return to the next level up though I suspect 120 would be problematic.

I would also recommend you have the latest Nvidia drivers installed and use Display Driver Unistaller (DDU) to ensure a clean install of updated Nvidia driver (its a free app).

And as I mentioned above I would definitely check for a potential overheating issue.

 Oh...I think I'd try leaving the numslices to '4' for testing these other settings.

Good luck and please report back your progress.

[anpeaco]

Wow, thanks for taking the time to send that through, that's a lot of work. I've had some progress tonight. I uninstalled everything oculus, tray tool etc, cleared out the registry of any Oculus settings reinstalled, and retested. I'm running at 72 fps, but with my resolution slider at max in the Oculus app (I have run like this for a long time) Over the past 6 months I have seen this happen very occasionally without fully realising what was happening, it feels like this has started to happen much more regularly more recently though and has been much more severe. It always starts with the lowest slice starting to brighten, the over time it turns to pink, and the next slice up starts to brighten etc etc. The increase in frequency probably coincides with a number of changes which have taken place over this period, upgrade to Windows 11, updates to DCS, updates Oculus and Nvidia drivers. But I cannot directly attribute it getting worse to any of those changes directly. It has worked fine one Win11, on the latest DCS update so unlikely to be those. 

After reinstalling tonight I still got the problem at 4 and 1 slices. I then played with some settings in Oculus debug tools,  encode res to 0, dynamic bitrate to enabled, bitrate max to 0, encode bitrate to 0, and numSlices back to 1 again. I have just managed a full session of 2 hours without trouble! I had tried the 1 slice setting earlier though so I'm not sure if this was just coincidence. I'll have another session tomorrow and see if anything returns, but it does seem like one of those debug settings has done something and things seems to be back to normal again, hopefully.

I had previously has encode bitrate at 400, and encode res at 3600, and it was running fine with those settings previously. As I said previously, it does feel like there are so many variables with getting this all to run well, most of the time seems to be spent tweaking settings rather than playing anything!

Thanks for your help though, I will have a look at monitoring GPU temps and have a play around with the VRAM settings you mentioned.

[benji94]

Yes, that sounds like progress and an affirmation that the issue is related to the settings and their impact on the GPU encoder to keep up.  

72 with the resolution slider all the way to the right should be ok.  However, be sure to leave the ODT pixels per display override to '0'.  

By the way, the ODT and the OTT (third party app) does exactly the same thing.  You should use one or the other but not both.  You don't want conflicting commands from these apps sent to the Oculus Link runtime.  All either one of them does is provide text commands conveying the parameters you've set to the Oculus software when it loads.  The Oculus software calls upon the ODT (or OTT) one time to obtain the settings and that's it.  I'd recommend just using ODT since it is after all provided by Oculus.

Yes, there are a lot of settings to be sure.  They all need to be in sync in order for this whole mess to work as intended.  A change in one can have unexpected and not easily diagnosed impact on some component of the system.

Once you feel it is stable again then try increasing the settings one at a time to improve visuals if you need to.  I would keep the encode resolution width to 3664 though since that is native.  I'd keep the bitrate to default as well for a bit and then maybe increase 50 at a time.  I never go over 250 by the way.  Also, as I mentioned, reducing the FOV tangent multiplier can help significantly in reducing rendering load on the GPU but without any noticeable degradation in visuals (the periphery will be less clear but the center where you focus anyway will be better).  Just play with the FOV settings.  You can gain a lot by lowering the vertical setting over the horizontal setting without even noticing the reduction in FOV.

Also once you have stable settings you then might be able to try increasing the numslices again.  The higher the number of slices the lower the latency but with DCS it might not be all that necessary.  With racing games it is though.

Martin Rakver wrote this excellent explanation of all the ODT settings:

Oculus Debug Tool Guide for Quest 2 (Why & How To Use) – Smart Glasses Hub

Good luck.

[TheAdipose]

Delete the registry item and it will go back to normal. Don't change it to 5 because if you then start airlink then you've forced it to be 1. The metapro Reddit has more on this

[zheiko.nileth.3]

So, I can enforce the issue by overclocking my GPU, so I have tried OCing it and of course the white bar appeared

Ran through the slices all the way to 1 and always had the white bar appear - at the latest setting of 1 I actually had the full screen slowly whitening more and more.

Just for the giggles I set slices to 8, played now for 30 minutes with OCed GPU and no issues.

Interesting...

[Requmor]

hi! how can this problem be solved? I reread a lot of topics, but I did not understand which one could help, at least approximately.

[Requmor]

I have already found a solution, a solution using cmd helped me personally. but seeing what work you have done in finding these mistakes, I want to thank you on the other hand. it's really great

[andrea.maccapani]

ciao

I experienced the white/pinkish stripes on one/third of the bottom row just playing DCS.

after some tests, and following the suggestions, I tried to setup Oculus onas a matter of fact I tried few settings and what worked best for me is 

in Ouculus APP, Device, and set it to a refresh rate of 72hz, but with a resolution render of 0.7 (2944x1504)

in OTT i use a Default super sampling of 1.2, ASW mode @45hz forced, Adaptive GPU scaling off; the Distortion curve to Low, encode res to 2912, encode bitrate 250 and Dybnamic Bitrate max 250

I have a I5 9600kf, 32 gigs, 3070 Ti.

ciao