I've been running Linux Mint 17 for the last half year with no fan problems, but last week the laptop fan turned on and hasn't stopped since. I hadn't messed around with bumblebee or nvidia drivers since I first installed Linux Mint 2 years ago, so what changed? I updated to Mint 17.1 hoping to fix the problem but the fan is still going.
I suspect the loud fan is from the graphics card no longer being managed correctly. I purged bumblebee and nvidia drivers then reinstalled bumblebee 3.2.1 and nvidia-331. Fan still going. I did the following check to see if the computer knew where the discrete and integrated graphics cards were and it was correct:
$ glxspheres64 Polygons in scene: 62464 Visual ID of window: 0x20 Context is Direct OpenGL Renderer: Mesa DRI Intel(R) Ivybridge Mobile 61.013470 frames/sec - 68.091032 Mpixels/sec $ optirun glxspheres64 Polygons in scene: 62464 Visual ID of window: 0x20 Context is Direct OpenGL Renderer: GeForce GT 620M/PCIe/SSE2 108.834153 frames/sec - 121.458915 Mpixels/sec
I'm stumped. What's causing the fan? What am I missing? Let me know if other system info would be helpful!