MSI GP66 & HTC Vive Pro - Must restart laptop to use headset?!

[Tomie]

Title is exactly my problem... But let me explain. 

I got a brand new Vive Pro with the base stations, controllers, tracker 3.0. 
My current system for VR is an MSI GP66 Laptop that has an RTX3070 MaxP (MUX Switch enabled), but the issue is it only has MiniDP & HDMI outputs. Therefore the HTC provided MiniDP to DP cable is not suitable for me. I did some research and as mentioned by user "HackPerception" here : https://forum.vive.com/topic/7268-where-do-i-get-mini-display-port-to-mini-display-port-cables/ I purchased (a considerably expensive) cable : https://www.amazon.ca/Cable-Matters-Mini-DisplayPort-Black/dp/B00ESM3DKA?th=1 that was confirmed to work with the headset. 

Prior to my getting my Vive Pro I was using a Quest 2 with absolutely 0 issues. I never had any HMD connection issues. 
For some reason, I can not use my Vive Pro headset as it will constantly lose connection and give an error "Your GPU is having trouble communicating with your HMD resulting in an HDPC error". 

After hours or trial and error, the solution is to connecting my Vive and get it all setup (turn on the breaker box, plug everything in), then reboot my laptop with everything on, and suddenly it works perfectly. 
But this will only last until I turn off the breaker box and disconnect the headset. Even Exiting VR, it works perfectly again (without restart) so long as I do not disconnect any cables or turn off the breaker box... 

I have updated the headset drivers/firmware, running the latest Nvidia drivers as verified in GeForce Experience. And I will re-iterate that I am running in dGPU only mode, the iGPU is disabled via the MUX switch in MSI Control Panel. 
This is really annoying, and honestly sad coming from a product costing DOUBLE what the Quest 2 costs... 

[HackPerception]

@Tomie - This is a super weird one. I have never heard of a case quite like this.

• That cable I linked has historically been $6. I'm sorry that listing skyrocket an absurdly high price. The 6 footer is still cheap - it's probably one of those supply chain things where Amazon sold out and hasn't gotten a resupply.
  • You generally want to aim for Displayport 1.4 cables that can support 4K @ 60fps. 2 meter cables are usually the max, with best performance on 1 meter cables.
• Quest 2 doesn't connect to your dGPU directly. What you see on Quest 2 is a compressed video that's being transmitted over USB/WiFi. PCVR headsets are creating an uncompressed video link directly from the headset to the dGPU. It's a different approach.
• The issue you're having with mains power is super weird. We have seen examples in the past where basestations can be affected by unstable power supply. E.G. A high-draw device like an AC or dishwasher kicks on, and it affects the quality of the current supplied to a basestation causing them to spin at an incorrect speed causing tracking lost.
  • You could try to temporarily disable high-draw devices to see if something is spewing out electrical interference.
• If you have access to another VRPC, you could use that to isolate it between the laptop and the headset.
• You could have a bad power supply on your laptop or a faulty motherboard

Pretty weird situation that would be very hard to troubleshoot without physical access. 

[Tomie]

Oh, hey! Appreciate the reply. 

I don't have any other VR Capable PCs. What I suspect is it's maybe in how the GPU handles the different video outputs. 
It's likely something that could only be resolved with either : gpu firmware update, BIOS update, (unlikely) driver update. 

I don't think I will ever have a solution to this issue. I was more so posting to vent//make anyone else in a similar situation aware to a potential workaround. If I ever solve the issue I will be sure to share the research & findings.