Please help me. I have ubuntu 14.04. When I use nouveau driver gpu temperature don't up more then 70°C. But when I switch to nvidia-331-proprietary my temperature jump to 90°C or even higher when start 3D app's. I have lenovo g560, nvidia 310m, without optimus.
You could try running:
And under the PRIME Profiles tab on the left of the Nvidia settings window switch to your Intel GPU instead of Nvidia GPU. This will turn off the graphics card and help with cooling, but isn't going to help with cooling when you want to use the graphics card.
Though you can change settings there to limit how much power the graphics card will use.