Hi @hitenter,
I have a RX 480 in my machine. I have this problem as well. It is on my list to fix eventually to work with the Split kernel, but until that is done you can make Raytraced/Cycles use the so-called mega kernel. You’ll have to add an environment variable before starting Rhino WIP:
RMB on windows start menu > System > Advanced system settings > Environment Variables… > New…
Add the variable CYCLES_OPENCL_MEGA_KERNEL_TEST and set its value to 1.
edit: Note that you’ll have to give the first attempt to switch to Raytraced time to actually compile the mega kernel. This process can take up to 10 minutes.