Thanks to a blog post in Lizards by Nelson Marques, I’ve solved noisy fan issues on my Radeon HD4650 box so - Mini Howto - Quieten your Radeon System with FOSS Default openSUSE “radeon” Driver
If you’re fed up of 3D Accelerator fan noise in default openSUSE this could be a good solution, please help improve the documentation or suggest improvements if you can.