I am using Linux Mint 17, and I am very happy that I was finally able to get my GPU to render on it. My problem was that I needed to properly run Blender as root. However, when rebooting my computer, I need to run Blender in root again to make the GPU rendering work. This would be fine, except for the fact that everything written to the hard drive by Blender is owned by root, and cannot be edited unless running everything in root.
I've heard that installing nvidia modprobe will allow programs that use CUDA processing without running the program as root. I have tried to install this in a number of ways, and it doesn't appear to be working.
Does anybody have any suggestions? (It's possible that I'm not properly installing modprobe, but I've tried both suggestions on this answer: CUDA rendering on Linux Mint or Ubuntu variants)