I bought the flashed Nvidia GTX 980 Ti 6 GB for my cMP 5,1 a couple of years ago and generally it's been a success. But there is regular glitch that occurs both within Premiere Pro 2018 and in Finder and other apps. In Premiere the video image sometimes goes to black in the viewer and sequence monitor windows. I still see everything else - name of the file, folders, timeline, etc - but not the images from the media. This happens when there's a lot of different media in the Premiere project and the fix is to close it down and re-open it. Sometimes it will happen repeatedly and almost always after I've been working for hours. So is heat an issue?? Or RAM (I'm working with 34gb RAM in my Mac Pro 5,1 12 core, 3.3ghz on OS El Capitan). I've switched from CUDA to OpenCL when the vision has gone to black and the image does come back but the performance of OpenCL is not great of course in Premiere. In the other apps around the same time of the day I get these glitchy squares as in the attachment. Any ideas?