On CC2015 it should be enabled, at least on a PC with nVidia I know this to be true. I do not know the tools for verifying GPU usage on a Mac. Look at Files/Project Settings/General (or the Mac equivalent) and see if you have the option to use OpenCL for Rendering.
You may need to update your GPU drivers
Thanks for the reply.
Im on a Mac. I have been onto Adobe and they have told me my graphics cards the AMD Radeon R9 M290X 2048 MB is not compatible with premiere pro and AF so therefore unless. They require a Nividia card.
Ray traced 3d Wont work with the AMD Radeon R9 M290X 2048 MB card, its very frustrating.