So I have a MacPro 4,1 upgraded to a 5,1 with 32GB of RAM and an NVIDIA GTX 670 with 4 GB of RAM. I am running the system off of an SSD via a sonnent temp pci adapter with a usb 3 card and a BlackMagic Intensity Pro 4K. The system used to run fine, but is hitting the point where it crashes all the time. I had been running the Apple video driver, and it was working fine, but then the crashes started happening all the time. I switched to the NVIDIA web driver, and the crashes stopped normally, but still occur when I try and run any CUDA program. And even normally I still get random restarts. And opening premiere shows some crashes to do with the web drivers. I am thinking maybe the video card is failing. I have run Diskwarrior and it shows no errors, and I ran TechTool Pro 12 and it passed all the video memory tests. Anyone have any ideas?