I've install it directly from the Arch repos. And with a mobility radeon X2300, default setting, my computer is moving from 40°C to 50°C. By the way, I've no 3D cool desktop stuff. And KDE4 can provide this to you, like a really cool desktop cube for desktop switching. i love it with only 12 desktop. But I've problem with some app and this. Like dragon, the video player. Blender is not usable too with 3D stuff actived. But I suppose it's related to my graphic card. For wikipedia, this one support openGL 2.0. But my system say openGL 1.3 mesa 7.4.2. May the luck be with you, for this try ;-)
