Guys, there is some issue with the latest 3 driver versions from Nvidia that is causing FCPX to render incredibly slow.
Roll back to 378.10.10.1025.104 to resolve this issue.
Easiest way to do this is to use the nvidia-update script in Terminal:
Code:
bash <(curl -s https://raw.githubusercontent.com/Benjamin-Dobell/nvidia-update/master/nvidia-update.sh) 378.10.10.10.25.104
Restart and rendering will be fast again.
For example, on latest Nvidia driver, my 980ti was rendering BruceX at just over 1 minute 33 seconds.
After rolling back to driver version .104, I'm back to 31 seconds.
EDIT:: After you rollback the drivers and restart, upon logging into the MacOS desktop you'll have a popup window saying that there are newer Nvidia drivers available. Make sure you check the box that says "don't notify me about this update" and hit CANCEL.. otherwise it will install the latest driver and your work will be null and void.