I have been using Windows (Vista and 7) for quite some time on my DELL Studio 1555 and I have never experienced overheating problems (even when rendering videos etc.) but as soon as I turn on my laptop with Ubuntu, the fan starts spinning at full speed and the temperature starts rising steadily. The temperature rises to a point where the laptop shuts down due to too much heat!
Here are some additional details: Laptop model: DELL STUDIO 1555 BIOS version: A13 (latest, as per DELL website) Graphic card: ATI Radeon HD 4570
I did a clean install of Ubuntu 12.04 and have upgraded and updated everything, and the problem still persists.
This seems to be a common problem with many DELL laptops but I have not been able to find a proper solution...