Do I need a link cable with the Oculus Quest 2?

That worked. Many thanks.

1 Like

No you don’t which is what’s nice about the Q2(wireless or wired). The Quest 2 via Virtual Desktop is capable of obtaining the same performance/quality or better than using the Link cable. Of course this depends on dialing in both SteamVR/VD settings and your 5Ghz wireless network capability.

I’ve dialed in my settings and can obtain 24-30 FPS with MSFS2020 Ultra Settings using my Quest 2 via virtual desktop. I set my streaming bitrate in VD to 73Mbps with 100% resolution scale within the SteamVR application. I have been going back and forth between using Link and VD with the the same Ultra settings set in MSFS220, and quite frankly I’m obtaining the same FPS/performance/visual quality via virtual desktop as I do with when using the Link cable. The only drawback using VD is battery life opposed to using Link which trickle charges the Quest 2 while using it.

Here’s a screenshot taken via VD screenshot tool during one of my flights. Sorry screenshot is compressed until I figure out how to retrieve the uncompressed version from Virtual Desktop’s file structure.

1 Like

Hi I’m a new Quest 2 and HMD user. I manged to get MSFS to play wireless after a lot of configuration and testing. I still have some doubt:

Does Nvidia driver version 466.14 still makes a difference for Quest 2 + VD Streamer due to the SteamVR bug? Or I can update to 457.30 or any latest driver? I’m using 1080 Ti so I don’t need the latest driver.

I’m using SteamVR Beta 1.16, and tried 1.15 stable, doesn’t see much different. I can’t get 1.14 Linux to work, anyone has any luck or does it make a different too?

Not sure what SteamVR bug you talked about is, but I did find that SteamVR occasionally failed to load MSFS VR (only seen blue or grey voidness even if I could see 3D cockpit with SteamVR menu in front before pressing left menu key). I had to load MSFS directly from VD without starting SteamVR first (it would still be loaded but was never in the way) to avoid that annoying issue. If the space bar didn’t respond after that in VR, it’s because SteamVR took the focus, so clicking MSFS icon on windows task bar would help.

1 Like

While setting up my new Oculus Q2, I was having success and then after loading Virtual Desktop, when I removed my headset, all my monitor screens on my pc were black. Windows was running but no signal is being received on my monitors.
I can only reboot by cold shutting off pc, and it come up black every time. How could Virtual desktop effect my monitors like that on Win 10?

VD streamer has one optional (not default) setting which will log you off when exit VR. Maybe you can uncheck that.

Last night I tested Oculus Link again, using same SteamVR set-up as with WiFi. Although Oculus Link connection test showed 1.7GB/s connection speed, MSFS VR was still unplayable because performance was horrible.

It’s well documented in other thread. If most of the Quest 2 users doesn’t know about it I guess it’s not an issue over here.

It might only be due to the combination of Display Port and SteamVR to the headset which causes the problem. AFAIK what we see in Quest 2 is streaming encoded video, that’s why the latency is higher.

I am wondering if the connection speed of 1.7 is high enough? I get about 2.3/2.4. Are you using a usb 3.1 connection or usb 2? If usb 2 I would try a usb 3.1 port.

I have USB 3.0 port but on an 8 year old main board. Lots of other USB ports are used so maybe the actual USB 3.0 bandwidth is even lower.

Nevertheless, the tested results of 1.7 GB/s should be more than enough for MSFS data transmission, but the performance was still much more horrible than using WiFi streaming.

The WiFi streaming is quite impressive TBH. I can even cast the gameplay onto a TV while playing with WiFi streaming.

I really hope some tech people can explain to us how WiFi streaming really works and why it could do so well: With bandwidth remain the same, what’s the main (design and programming) factor to decide a WiFi streaming performance? How high priority is WiFi streaming normally given in CPU processes? Does it ever utilize GPU or Quest 2’s own calculation power?

Yes, the Nvidia or the AMD GPU on the PC and the GPU of the Quest2 both have accelerated instruction sets to do the encode and decode required - the H.264 ( or other choices )compression algorithm usually provides about a 10 (and as high as 50) to 1 reduction or more on the amount of data for a given image. If you get the performance display enabled on the Virtual Desktop application, you can get an idea of how many milliseconds the PC GPU takes to do the compression encode, then how long it takes to get that over WiFi to the Quest2, and finally an estimate of how long it takes for the decode by the GPU of the Quest. The last two elements only add to the latency between the PC and the Quest2 whereas the encode which takes several milliseconds does add to the frametime and reduces the FPS. If you do the math on the Quest2 resolution for the final transfer to the Quest2:
1832x1920=3.5Megapixels or 28 megabits, then divide by 1Gbps for the approximate speed of the wireless connection in bits-per-second, then divide by 10:1 for the compression, you get about 3 milliseconds for the actual frame transfer. Add the decode time of several milliseconds on the Quest2 and you get the added latency. The math for the Link should be nearly the same since it is a serial transfer as well and the Oculus app test of the Link usually reports about 2 Gbps which is somewhat (maybe double) faster than wireless. The difference in the image quality should only have to do with the parameters of the encode-decode sequence.

1 Like

But, but…
I another recent post about the usb cable for link, I did a measurement of the real traffic on my usb cable whilst I was in flight , 2000 feets, in the TBM, very smooth even by turning head left and right, and the used bandwidth was 88 Mbps at max… On a cable tested at 1.7 Gbps !!!

So we never use that bandwidth at all with usb link…

Virtual Desktop has a setting (withing the VR app, not in the Windows streamer app) that allows it to change your desktop resolution to the optimal resolution for VR depending on your headset. It probably switches your monitor to an unsupported resolution setting. When you switch it off things will probably return to normal, or maybe it won’t trigger this problem again after restarting your computer.

1 Like

Thank you for the good explanation. I have one more question: is it possible that Virtual Desktop was programmed in such a way that its stream encoding and decoding are more efficient than those behind Oculus Link? If so, for low end PCs like mine, using VD may see better performance than using Oculus Link, while better PCs won’t see much difference.

I am in the process of evaluating that…
With Link cable , I get audio dropouts, which MAY be indicative of DATA Drop out . With Virtual Desk Top,I have not seen this problem, but…

  1. I cannot use Virtual Desktop unless I change my OpenVR Runtime to look at SteamVR openXR. My FPS counter via Developer mode cannot be viewed, thus FPS cannot be evaluated… It is offset to the upper right and unviewable even by rolling eye to view. Am I the only one?..the only alternative is FPSVR via Steam, but that may cause some effect on FPS itself, since Link cable does not use SteamVR.

regards,
Chas

I use FPSVR just when needed to figure out the fps impact of my settings, then disable it when I’m set since it causes stutters for some reason.

Yes, I tried Link again last week for a few hours and definitely always get better performance with VD. Also sometimes have glitches with Link while VD is always clean.

1 Like

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.