Quest 2: Anyone tried AirLink yet

[ShaunOfTheFuzz]

On 5/4/2021 at 12:09 AM, Nealius said:

 

I tried some of the tweaks you mentioned plus some additional stuff. Oculus res 1.2, DCS PD 1.0, terrain textures low, textures medium, water medium, removed some parked aircraft in my missions, uninstalled MSI Afterburner, disabled Windows Defender, upgraded from my 700W PSU to 850W (probably doesn't matter). Now I have smooth performance often locked at 36 with no artifacting, no Link stutters, and no audio stutters. Yet......

 

 

Hey that's great! Glad to hear it helped. There are going to be some circumstances on the supercarrier and extremely busy situations where you might get drops, but that's just DCS for now

[Nealius]

45 minutes ago, ShaunOfTheFuzz said:

 

Hey that's great! Glad to hear it helped. There are going to be some circumstances on the supercarrier and extremely busy situations where you might get drops, but that's just DCS for now

 

Well, I spoke too soon. The white bar came back with 7.5GB out of my 8GB of VRAM being used. At this point I just gave up with tweaks and got a 12GB 3060. 

[Skwirl865]

On 5/2/2021 at 4:33 AM, ShaunOfTheFuzz said:

Don't use HWinfo or whatever, use task manager > performance > GPU. Windows shows usage rather than allocation and what those other monitors don't show you is the shared video memory being used, which windows does show. Some VRAM is hardware reserved (about 149mb) so when I start dipping into RAM I'm seeing my VRAM at 7.8/8.0GB, but when I look at shared video memory I see it go up to 8.5/40GB. This tells me that windows has apportioned 32GB of my system RAM (I have 64GB) as shareable video ram, the 8.5GB tells me that windows is now using 600-700mb of that RAM. Your sig says you have a 2070; I have a 3070 and I can't run high terrain textures, high cockpit textures, MSAA and a decent resolution without way overdrawing VRAM and tanking my performance.

Unless you're running your quest at a low resolution (and no MSAA which costs more VRAM based on resolution) then you're dipping into shared memory, which has garbage performance. 

Terrain textures to low is a no-brainer, the differences in terrain textures are minimal except in Syria and even then it's mostly just sharpness. Terrain textures cost >700mb of VRAM for a tiny amount of gain in visuals (I've found the VR shader adds more sharpness anyway). 

 

The main textures at medium are a mixed bag, and you can get away with high textures if you run lower res or disable MSAA. Personally I run my res at about 4864x2448 with 2x MSAA. You can swap out MSAA for high textures here, but you won't be able to run high terrain textures with high cockpit textures on an 8GB card. At Medium textures, modern modules like in the F-18, A-10Cii and F-16, remain very readable for me especially with the sharpening mod, but some of the older modules can be blurrier. Low textures look terrible IMO and are a different story. The problem with textures is that they don't just apply to your cockpit, but to other jets and external models, etc, so you can get really bad hits in crowded conditions. 

 

This is typical of the VRAM issue. It doesn't always happen because sometimes a particular set of circumstances will let you skirt the issue or recover. But if you have the Syria map and the A-10Cii module, then try this:

Load into free flight, orbit around the city you start over and then open the F-10 map and quickly zoom out to full zoom. You'll see the map stutter and hitch and then when you close the map you'll see the ground textures have to load back in from low LOD. Check your shared video memory usage in task manager and you should be well over 8GB. Quiet often this will result in a framerate in the single digits very quickly.

Once it happens in a mission, it will stay, it's like the oculus encoder never fully recovers, you need to exit the game and restart. If you look at task manager you'll see that DCS often doesn't release VRAM in these circumstances, I've seen VRAM remain at 7.8GB in the main menu after having an overrun.

What is the “vr shader” and “sharpness mod” and do they pass integrity check?

[AlpineGTA]

This might seem completely obvious with hindsight, but now I'm using my Quest 2 with AirLink the only thing that was limiting my flight time was the battery draining down. But then I realised I could use the Link cable, that I was no longer using to connect to the PC, instead I could plug it into the charging plug and keep the headset fully charged while I'm using it. It does mean I have a cable coming out of the side of the headset again, but when I was using the Link cable to the PC the battery would still drain down. This way I can fly for as long as I like.

[VR Flight Guy in PJ Pants]

News: it is reported that the PC Oculus app has been updated to support 120Hz for both Oculus Link and AirLink. Not seen it yet personally, but I suspect it may help the performance a bit. Note that you also need to enable the 120Hz feature within the headset as well to use it.

[dburne]

18 hours ago, VFGiPJP said:

News: it is reported that the PC Oculus app has been updated to support 120Hz for both Oculus Link and AirLink. Not seen it yet personally, but I suspect it may help the performance a bit. Note that you also need to enable the 120Hz feature within the headset as well to use it.

 

I would think a higher refresh rate would more hurt performance rather than help.

[VR Flight Guy in PJ Pants]

I dunno, I have yet to get 120Hz enabled yet. If anyone has tried it, please post the comparisons. Thanks.

[Supmua]

I’m gonna test it but don’t expect magic.  I don’t think there is any wifi bandwidth that can support full 4K120Hz without significant video compression.  Even the USB 3.1 port on the Quest2 headset can only push 4K60Hz. 
 

As far as I know you need either DP 1.4 or HDMI 2.1 to handle 4K120Hz.  And that’s why the new Vive Pro 2 will use some compression trick to push 5K120Hz.  

 

Edit:

I still have the v28 version, going to wait until it decides to update I guess.

Edited May 20, 2021 by Supmua

[AlpineGTA]

I thought I'd try it out of curiosity. I enabled 120Hz in the headset but I didn't see any difference at all, although, even though I'm on v29 I couldn't see anywhere in the desktop software to turn on 120Hz, so maybe I still don't have it enabled yet.

[Supmua]

OK I did try Air Link 120Hz for a bit.  Had to disable Air Link first and run it in Link mode, then switch my headset to 120Hz in desktop app, then enable/pair Air Link again.  It does work in DCS as the ASW kicks in when I fly around with my framerate count staying fixed at 60 fps (2:1 reprojection).

 

Not impressed with the image quality at all, it's quite blurry/muddy and I can't read DDI/MFCD unless I lean in.  I can tell it's not running at full screen res, that plus video compression--and this is with 1.2x rendering.  It's like watching a 720p YouTube stream on your iPad--passable but definitely not for me.

 

And this leaves me an impression that wireless VR might not be ideal for flightsims due to significant bandwidth required to deliver high res graphics, unless you are fine with blurry images. 

Edited May 21, 2021 by Supmua

[AlpineGTA]

So do you see an option in the desktop software to turn on 120Hz? Is it on the same Beta tab as where you turn on AirLink?

[Supmua]

The entire process is a bit convoluted, and I think this is because it is still experimental. 

First you have to enable 120Hz option in the Quest 2 native setting in Experimental section. Then in desktop app setting, go to Devices section, click on your headset image and you can change refresh rate and supersampling/resolution from there. 

Edited May 21, 2021 by Supmua

[AlpineGTA]

I enabled it in the Quest 2 experimental section but I still only have up to 90Hz when I click on the headset in the desktop devices section. Maybe it's just not fully unlocked yet on mine. It took a few restarts before I saw the AirLink when that was first released. But thanks for clarifying. 

 

I doubt I'll use it anyway. From your test it doesn't sound like it'll be much use for DCS, I was just curious to try it.

[5ephir0th]

Don´t expect 120hz will gives you better results unless your hardware is capable of, at least, run 60 fps stable, below that you will run full of stutter

[AlpineGTA]

28 minutes ago, 5ephir0th said:

Don´t expect 120hz will gives you better results unless your hardware is capable of, at least, run 60 fps stable, below that you will run full of stutter

 

Yes, that's why I'm thinking it won't be much use for DCS. I can get 60 - 70+ fps in some single player missions, depending on map and module, but I'm usually happy just to have a stable 45fps (or lower, as long as it's smooth). Still going to try 120Hz at least once though, just for the craic, to see how it performs and looks.

 

(I just noticed, the spec in my sig is well out of date and not what I'm running! I should change that.)

[Supmua]

I’ve been aiming for 40 fps on my Valve Index setup (80Hz mode) with all the graphics options and high supersampling and it’s been great.  Don’t really need 120 or even 60 if it won’t give me good graphics. 

[VR Flight Guy in PJ Pants]

I follow the instructions above:

 

Disable Air Link

Connect up the USB-C cable

Connect with Oculus Link

Find the 120Hz setting in the PC app

Turn it on and find the resolution ratio changes!

Keep the ratio

Disconnect, re-enable Air Link, connect again

Run DCS World in VR

See 120fps in the main menu

And yes, the frame rate improves a bit, but the MFD text gets worse, but the HUD text is okay.

Raise the resolution does not improve the clarity much, but the fps suffers

 

Conclusion: I am a guy who value frame rate over image quality. Nonetheless, 120Hz does not worth it at the current state, since it is still experimental, I think there is still a chance to make the DCS World more enjoyable.

[Recluse]

18 minutes ago, VFGiPJP said:

 

Conclusion: I am a guy who value frame rate over image quality. Nonetheless, 120Hz does not worth it at the current state, since it is still experimental, I think there is still a chance to make the DCS World more enjoyable.

Agreed!  I haven't unlocked the 120 Hz yet, but I did try up to 90 Hz. At first I could NOT make an air link connection above 72 Hz but I could go higher with the Cable. Now I can get it working at 90 Hz and the suggested resolution. FPS is a bit higher and it is smooth, but I am torn between this and going back to 72-80 Hz and cranking the resolution down a notch. The clarity is NOT much different and the 36 FPS vs 45 max between 72 and 90 Hz doesn't make much of a difference.  Going to try and split the difference and go to 90 Hz and pull resolution back down to the second notch on the 1.0 setting to see how that goes. Honestly the lower resolution actually gave a bit better clarity. I turned Pixel Density to 1.4 or 1.5 in DCS and it seemed like those settings with 1.0 resolution and 72 Hz gave the  best overall experience.

[Supmua]

The current Quest headset is physically limited by the bandwidth of WiFi or USB 3.1 for PC tethering.  However, AI upscaling technology similar to NVIDIA DLSS could help improve the final image rendering, so I think there is still some room for improvement.

 

For complex PCVR games/flightsims, I think wired headsets is still the way to go as these have video ports that can support higher resolution—for the same reason you do not connect your PC to a monitor wirelessly.  DP 1.4 in current gen headsets can provide 32 Gbps bandwidth (HDMI 2.1 has 48, and DP2.0 can go up to 80!).  In comparison, the USB C port on the Quest can only support 10 Gbps which is barely enough for 4K60Hz without compression.

[VR Flight Guy in PJ Pants]

On further thoughts, it does not make sense that higher refresh rates actually lowers the frame rate when other settings remain the same. I dunno but I suspect there may some sort of tricks Oculus is playing with 120Hz. They are not telling so I have no proof whatsoever.

 

Another factor we have not discussed is the bit rate. By default, the bit rate for Air Link is variable. I fix it at 85 for now. So it plays a part, wired or wireless, about the quality.

 

In an ideal world, we can go to the highest resolution, max out everything, but now we are more or less "stuck" with the choice between quantity (frame rate) and quality (visual)

 

When there is any further updates, we shall see how it goes.

[Supmua]

This is an old article but it has some good info on compressed video streaming and bitrates on the Quest. 
 

https://servreality.com/news/the-oculus-test-update-link-allows-you-to-increase-the-bitrate/

[Recluse]

I've not been able to achieve an AIR LINK connection above the Default 0 setting (assumed to be 150?).

 

With the cable I can bump it up to 500. BUT i honestly haven't noticed MUCH difference. 

[Supmua]

7 hours ago, Recluse said:

I've not been able to achieve an AIR LINK connection above the Default 0 setting (assumed to be 150?).

 

With the cable I can bump it up to 500. BUT i honestly haven't noticed MUCH difference. 

The default setting uses dynamic bitrate 100-150 and it might be best to leave this alone for now.  I think a high end GPU (and maybe CPU as well) is needed to encode higher bitrate, else stuttering would occur.  I also find Air Link to be inconsistent in terms of performance vs USB cable connection.