The Quest can be a PCVR headset with a 3.2 Gen 1 cable, ie 5 Gbps. How different is this?
I’m pretty sure outboarding most of the hardware that’s not speaker, camera, or screen is plenty doable. It just blows Meta’s selling point of making it a self-contained device. I’d probably prefer it though, especially if I could attach the outboard module to the back of the head strap as a counterweight.
Hardware decoding / encoding all of those video streams requires a lot of processing power on both ends, adds 10s of ms of latency, and makes the video quality worse.
Let's say DSC is allowed, which costs microseconds and is basically invisible, and can compress down to about 8 bits per pixel.
That USB cable can transmit 20Gbps in each direction. The display needs to do 23 million pixels 90 times a second, and at 8 bits per pixel that's about 17Gbps.
The video cameras going the other way are 13 million pixels for the main cameras plus some amount more for the 6 tracking cameras and the other sensors. And those main cameras are outputting 8 bits per pixel before any compression is applied.
It's a tight fit at that bitrate, but we can upgrade to USB4 and get 40Gbps in each direction. That leaves plenty of room for everything, and makes sure there's headroom for HDR and 100Hz and whatnot. It works out.