Now that Oculus v17 software allows for a wider use of USB cables for Link I thought it would be useful for those that have both to share their views on each cable. It would be good if we could limit our discussions to these 2 cables rather than the multitude of other non-Oculus ones already in use and which have already been discussed in a separate (and long) thread. Also, it would be nice if we could limit discussion on this thread to PCVR via Link rather than discuss the wireless option with Virtual Desktop (again already a fairly long thread on this).
I bought the official link cable at the same time I bought my Quest 1.5 months ago. This cable cost me aud$129.
First of all, both cables actually work very well. I have not had any problems starting up Link with either. Initially (pre v17) I found I occasionally needed to plug/replug my official link cable a couple of times for a connection to be successful. Now all I seem to need to do with either cable is to simply start up my Quest, wait for the guardian confirmation, and then plug in the cable to my Quest. I get the message asking if I want to enable Link and after selecting this my Oculus app opens and I'm off to the races. Also, I'm using a direct usb type-c connection, without any adapters. I'm currently using a separate pcie usb3.1 gen2 card installed in one of my free pcie x16 slots. I got this one from Amazon for aud$36;
I initially just used a usb3.1gen2 type-c port on my Ausu ROG Maximus XI Hero motherboard and this worked fine but after a few connection problems I decided to try a separate pcie card. I'm not really sure if this has significantly improved things but since I do have a lot of usb devices installed (Rift cv1 w/2x sensors, Vive Pro, flight sticks, plus sometimes a few others) I thought it would be a good idea to spread out the usb bandwidth a little.
My official link cable connects (from the device connection test on the Oculus app) at 1.7Gbps, usb3.0.
My Quest usb2.0 charge cable that came with my quest connects at 360mbps, usb2.0. I do get the orange warning light that tells me it would be better to use a usb3.0 connection but this does not stop the connection itself working.
So far I've found that most PCVR games are playable with the charge cable but some more complex ones like Lone Echo and flight/racing sims start to lag/stutter a bit, esp. with fast head movements and/or fast teleports. The official link cable is not perfect either but on the whole it is much better. So for now I see little reason to use the charge cable other than for charging.
Neither offers the same performance/stability I get with my Rift cv1. I'd like to think that over time that Quest Link will continue to improve and maybe one day I'll be able to retire my cv1.
"In theory," because the official Link cable is fiber-optic, there should be less signal loss. But because:
The maximum length specification for USB 3 is 10 meters.
The charging cable is 3 meters.
The official fiber-optic Link cable is 5 meters.
The actual signal loss may be too negligible to measure. That's probably why use of the charging cable is now supported. The only other difference I can possibly think of, is latency delay, caused by the copper medium.
The other difference between USB 2 and 3, besides max bandwidth, is full-duplex versus half-duplex. The total data being streamed is small enough that bandwidth shouldn't be a factor, but there may be some occasional hiccups over USB 2 if the tracking data from the headset has to wait for a few milliseconds while a chunk of video data transfers to the headset.
When the game is less demanding, it may be easier to time the data transfers so they don't get in each others' way, but if the PC is struggling to get the frames rendered in time, they might have to jump the queue to get to the screen. These data transfer conflicts might lead to tracking lags, video stutters, or both.