I have a fairly complicated setup where I have 2 GTX 780s in SLI and use displayport to connect to my 4k display and then use the onboard Intel GPU to output sound to my AV receiver. Until today this was working perfectly but now when the TV is set to use displayport MST I get no signal if the Intel GPU is being used. I played around with changing the Nvidia drivers, Windows update, hard resetting the TV and nothing worked. Eventually I unplugged the HDMI cable from my motherboard and the 4k signal started working. I did a "rollback" on the Intel drivers and it started using the MS default drivers and this worked okay but I wanted to reinstall the latest Nvidia drivers which I replaced with an older version during my testing. Nvidia wouldn't let me update their drivers until I installed the Intel drivers. Trying to use the Intel drivers again caused 4k to stop working again. Has anyone had any experience with Intel drivers stopping Nvidia cards outputting 4k over displayport? It's a strange problem and seems to have come out of nowhere, I didn't do any driver updates or Windows updates prior to it happening.
