I'm having this problem too and the solution of turning off the GPU fro camera raw did not work from me. My machine is an i7-8700k, 32GB PC3000, Samsung 960 Pro SSD, and GTX 1080 ti. It takes about 30 seconds per image to open when I click Open Images in camera raw.
Annoyingly, I just upgraded from an i7 4790k and 16GB RAM. The images used to open up with 5 second delay on this system. Now it's 30 seconds an a better processor with more memory. Any ideas?