It was the video card that failed, it is replaced and everything is working great

So after some posts online at various forums, it seemed to be that my crashing issues were what I feared. My EVGA NVIDIA GTX 680 4GB was causing the crashes.

Unfortunately MacVidCards seems to not have had any stock since September 2016, so I wasn’t going to get a flashed replacement card.

So I started looking for a PC NVIDIA GTX 980 4 GB with 2 6 pin power supply. This was much easier said than done. There are still quite a few new 980’s out there, but most of them either have 2 8 pin, or 1 8 pin and 1 6 pin for their power supplies. Looks like with the 10 series out (even though those won’t work in a Mac since NVIDIA hasn’t bothered writing drivers for them) that the 6 pin 980 have become rather sparse.

Finally I was able to find a ZOTAC NVIDIA GTX 980 4GB AMP! Edition which had the requisite 2 6 pin adapters, and a bit of a speed increase over stock along with 3 fans instead of 2. I had never even heard of ZOTAC before, but most reviews seem like it is a pretty good company.

I got the card and installed it, no startup screen of course, but it runs great. And speed tests show it is about 100% faster than the 670 I had installed, and it works great, the crashes are gone. And Premiere Pro runs great!