Since the following message you posted indicates it is being reported, I would guess that it is, but the Montreal gurus again need to provide insight regarding the conflicting messages. So based on the messages you are seeing, I am confused as to whether or not your NVIDIA Geforce GTX 780 GPU is being utilized. For a MAC there is only 1 “Black-Listed” GPU and it is the NVIDIA Corporation-NVIDIA GeForce GT 750M : NVIDIA : 750M It is shown at the end of this email down below in blue. Starting with M/C 8.5 we no longer have a qualified GPU list. I think the GPU interrogation was more difficult to perform on a Mac as opposed to a Windows system, but the Montreal gurus are really the folks to provide insight.
It is possible that the GPU driver has an issue that MC is unhappy with and as a result GPU acceleration is disabled. If not, it would be disabled and the GPU work would be off-loaded to the CPU’s. If the GPU card met the requirements for MC, GPU acceleration would be enabled. The idea being that during initialization, Media Composer would interrogate the video card for the amount of resident Vram as well as its capabilities.
Starting with M/C 8.5 new code was added for GPU support. To find out the current NVIDIA GeForce driver version on your Mac do the following: Click on the Apple logo, top left of your desktop then About This Mac. Got the gang in Montreal that works on this kind of thing and LUTs.