It turns out the excessive heat and constant fan on my U400 was being caused by the switchable graphics, which so far have proven themselves to be more effort than their worth. The situation isn’t even that much better under Windows, not being able to play more graphically intensive OpenGL games like Minecraft (yes, I just that about Minecraft). Maybe the Nvidia cards are better off, but next time I won’t take that chance and just get a laptop without any kind of switchable graphics if I can.
I haven’t yet figured out how to get AMD card working at all under Linux, so if that’s what your looking for, sorry. The integrated card has worked surprisingly well for me though, so long as I stick to graphically simpler games. Minecraft even works well enough with it, maybe even better than it ran with the integrated card in Windows.
This article might also apply to other laptops with switchable AMD graphics that are running Ubuntu 11.10 (and anything based on Ubuntu). So if you have a laptop like that which you want to run cooler, keep reading.
