I had no problems with RX 480 on FCPX 10.2.3. Now with FCPX 10.3 I had problems with crashing, , but that has been sorted by disabling HD4600 graphics on my machine.
How to disable intel 4600? in bios? without it can't boot
Yes, is some kind of pillow for crashes FCPX but in Games like HOTS it give freezes and ultra low fps.Inject Intel = false is all I have set.