Comment 22 for bug 1361207

Ubuntu 15.10 status: Installing only nvidia-352 and nvidia-cuda-toolkit packages forces Blender 2.76 to be started as root for the CUDA option to be visible in Blender menus (no errors reported in Blender). Installing also nvidia-modprobe fixes this problem: Blender can be started as normal user.

Starting Blender as root naturally saves the project files as root:root as well, possibly also other files, including user preferences. The nvidia-modprobe package installation seems more like a requirement in this use case.