My setup:
Acer Extensa 5635ZG
openSUSE 11.3
KDE 4.6.1 (from KDE:/Release:/46)
Nvidia G105M (with 260.19.44 driver)
After the upgrade to KDE 4.6.1 I can hear that the fan in the laptop is working harder, and hence is noisier. Before I had KDE 4.5.x (from KDE:/Release:/45).
With top I can’t find anything that takes up more CPU than before.
At the moment I use Compiz instead of kwin. Kwin was a little choppy for me. (Same fan noise though.)
Have anyone had a similar behaviour? I tried to search the forum but I couldn’t find anything. (Might have searched wrong…)
IMO if you don’t have access to your prior environment you can’t possibly know for sure why you believe your fan is on more.
In any case, if your fan isn’t about to die you probably should be glad it’s working more… It should keep your laptop cooler.
BTW - IIRC if you’ve installed nVidia OEM drivers (from the nVidia repository) the nVidia Configuration X Server settings exposes among many settings at least one that should affect your fan… Off the top of my head some settings that might generate more heat include hardware acceleration, power saving settings that affecting stepping.