Have had some problems with getting the GTX480 (turned Quadro 6000) to not crash ESXi 6.0.0.

All afternoon it would lock up the entire ESXi machine when the VM to which the GPU was passed through was started.

I reset all the BIOS settings to default, and it persisted, then i remembered about allocating ALL the ram to the VM.
Made that change (made sure that all the ram was pre-allocated before VM was started) and now everything is running smoothly!

UPDATE:
Spoke too soon. Same issue with the Win10 VM crashing.

I came across this and implemented it, butno change.
https://www.asus.com/support/faq/1004170/

Some useful info here as well:
https://communities.vmware.com/thread/461404?tstart=0
https://communities.vmware.com/thread/518299?start=0&tstart=0

UPDATE2:

Went back in the BIOS to look around and the “Above 4G Decoding” option was set to Auto again (which I presume turns it on). I thought I had set it to “disable” earlier in the day, but maybe I didn’t change it once I loaded the BIOS defaults. I also enabled “intel vt-d coherency support”. Now everything works as expected. The win10 VM I have can receive the GPU and it shows up with no problems. I can start and stop the VM. All is well. That was quite a pain in the butt!