Meta Quest 3 bitrate and latency for PCVR over Wi-Fi 6e, Air Link, and USB C

[Maxxgold]

Can anyone provide this information?

The only interest I have in the Quest 3, is if it can provide a better experience than the Quest 2 for PCVR. 

The Quest 3 has Wi-Fi 6e capability, but will it improve latency and video compression of the Quest 2?

Right now the Quest 2 averages 47 to 57ms of latency, that and the video compression is unacceptable for people who use PCVR headsets with zero compression and 11ms of latency.

I'm going to order one from Amazon, so I can return it if it can't improve on the Quest 2, but any help before hand would be appreciated 🙂

[rmzalbar]

Well, I've done some more testing with performance overlay and the encode bitrate always respects the limit, whether it's on static or dynamic. Regardless of what bitrate or mode is used, everything looks normal until it suddenly slams to zero for several frames. Then it jumps back up to the static limit, or starts ramping up to the dynamic limit. It really acts like a network failure, but Virtual Desktop functions normally and remains stable at 6GHz. Airlink runs fine at 5GHz wifi6, this anomalous behavior is not seen there.

[Pandages]

@Maxxgold directly connecting to a GPU over DisplayPort or HDMI sounds like a good idea but it comes with a bunch of new challenges.  The biggest one is bandwidth: display cables can carry 40gbps or more these days.  The signal integrity on a high bandwidth cable mean good cable handling, cable management, and restrictive cable lengths.

USB 3.1 using a Type-C port is a lot more flexible.  Encoding the video data using H.265 or AV1 might cause some visible artifacts but cuts the bandwidth requirement from ~32gbps minimum to a mere 300mbps.  That's a less than 1% as much bandwidth required, which allows us to use: Airlink, USB hubs, extension cables, etc.

DisplayPort full-bandwidth cables *must* be optical to reach longer lengths. USB-C can reach 20 feet without optics, making it massively cheaper to replace.  And you can see evidence of this in the price for a replacement cable for The Index ($100-200) versus a generic 20gbps USB-C cable ($10-20).



I think that's a REALLY important point to make in this conversation.

[Pandages]

@rmzalbar One other element about the performance of 5GHz vs 6GHz, keep in mind that the higher the frequency of a radio signal, the less penetration through dense materials it will have (for the same transmit power).  It means that maintaining direct line-of-sight between the headset and the Access Point (which might be a wifi-router or mesh node, or Airbridge).

6GHz really, really does not like to penetrate walls.  It was bad with 5GHz but much worse with 6GHz.

Another example of the same phenomenon is in cellphone / mobile networks: 5G networks rarely penetrate into buildings and are mostly useful outdoors, but it only takes a hill or a tree to interrupt the signal.  Those signals have massively higher amplification but it's the same issue.  You can't really overcome physics 🙂

[rmzalbar]

I can safely say that the propagation/penetration limits of 6GHz are not a factor in my testing, as the router is about 6 to 10 feet away in the same room with unobstructed line of sight, and different positions in the room have been tested. The link speed stays minimum 2100+ but generally remains stable at 2400. I've also tested 80MHz to see if there's increased stability, and even performed a walkaround site survey (I'm actually the only 6GHz broadcaster as yet in my housing complex.) However, a ping test and a throughput test are showing no hiccups, and Virtual Desktop is running well with aggressive settings.

I'm seeing some reports of issues as well as reports that Quest 3 Airlink is performing fine on 6GHz even with aggressive bitrate settings, so I'm going to expand my testing to include a different host PC environment and an alternate 6GHz router.

[rmzalbar]

I've now tested with a separate PC and a completely different 6E router (Asus ROG Strix AXE16000, a beast of a performer.) None of my changes made a significant difference. Airlink seems to struggle to maintain stable performance on 5GHz AX, and fails to maintain stable performance on 6GHz AXE. Virtual Desktop runs excellent even at very high bitrates and quality settings on both protocols.

I have no way of testing this, but I have the impression that something is not right with the Link client side services on the Quest 3. I hope this gets addressed soon.

[rmzalbar]

My issue seems to be resolved, but a few things changed so I'm not sure what fixed it:

1. I added a *dedicated* router for the Quest, tplink AXE75/AXE5400, as a 6GHz access point.

2. Meta seems to have pushed a small update that improved Airlink performance and turned on a few features, even though I'm still showing v57 in the update/version screen.

I can now run Airlink with dynamic bitrate set to 200Mbps with only the occasional dip in quality.

So now I have the following (somewhat ridiculous) setup:

1. Asus AXE7800 as main router, servicing general devices and uplinked to cable modem.

2. Asus AX3000 router configured as access point, uplinked to the 7800, with one VR PC wired to it, and running a 5GHz band in the DFS range just for my roommate's Quest 2.

3. Tp-Link Archer AXE75/AXE5400 as access point uplinked to the 7800, with my VR PC wired to it, running just the 6GHz band at 160MHz width just for my Quest 3.

However.. it works, it's reliable for Airlink as well as Virtual Desktop, and the quality is excellent.

[Geezik]

Oh my, that's an expensive solution to the problem that shouldn't exist in the first place! 😉
Glad you sorted that out though!

[Katsuno221]

Go to Oculus Windows app and Set the Resolution on 1,5x and in Steam Vr on 200%.

then Go in the Airlink Menü, not the settings, this where you can exit it , and switch to fix bandwith and Set it up to 200mb/s.

its so nice , an i use it with 5ghz wlan.

today i played Derail ♥️♥️🥰🥰 it sooooo awsome with the Quest 3 , and HL2 Mod, Asgarth Wrath and and … Uhhh im in love with the Quest 3 since 3 weeks 😻😻

[rmzalbar]

By now many of you have probably seen the YouTube video on pushing the Q3 up to over 900Mbps on Airlink. Well holy #$@! it works. I'm using a static 700Mbps on Airlink with H.264, maxed out encode width and there's just no more artifacting nor perceivable latency increase. Virtual Desktop has also rolled out similar gains and is also incredible, supporting 10-bit video codecs and Snapdragon super resolution upscaling. This is a huge leap in quality and performance over the Q2, It's just... astounding. This is, presently, the best PCVR headset I've tried. Best in every category, no, but equal or exceed in most of them and no friggin wire!

[DaftnDirect]

It would be really useful hear what people are getting with different motherboard and cards, maybe we should create a dedicated thread for charging during wired Link play!

Edit: ok thread created, moved the charging posts over there!