Any news on this? I have the same problem with the D700/MacPro.
That has been ongoing since Adobe added Open CL support. The only real fixes are use Software MPE until Adobe updates again and see if they have resolved the Open CL memory management.
This is the most current comments on this issue that I have found so I thought I'd include my experience with this problem.
Just started using a fully loaded Mac Pro, dual amd d700's. Been using Adobe PP CC for at least a year for long 1080p, h.264 30-90 minute videos with some basic color correction. Previously was using a MacBook Pro 2013 which did a good job rendering- using Cuda, although I was hoping to speed things up.
First attempt at a 36 minute multi-track sequence (2 camera) was fast but resulted in a video with intermittent thin white horizontal lines. The short 10-20 second test videos I did before the full render looked perfect. I found a lot of discussion on overheating of the graphic cards and used SMC and even some ice packs and an external fan to keep temps at below 70-75 degrees Celsius...didnt fix. Shorter renders of 10-12 minutes seem to be fine. Tried mpeg2, single pass, unchecked max render/max depth...nothing worked for the full render.
Trying software only render right now which seems to be a workable solution from what i have found online but of course isn't really helping justify the Mac Pro at this point.
I have seen comments online that previous updates of Mac OS supposedly solved this problem, something like 10.9 I think, but not sure if that was accurate.
Anyway, hoping this is something that gets some attention, if anyone wants anymore info from my experience let me know, maybe it will be helpful- thanks!
...here are the final posts describing a fix after two long years of people desperately seeking an answer on that thread. Maybe next time go with Windows and NVidia :
Who did you contact at Apple for the GPU swap? Same issues but mostly with DaVinci Resolve. I export a project and import in Windows (Bootcamp) and it renders out fine.