Version: (using KDE 4.3.1) OS: Linux Installed from: SuSE RPMs I would like KDM to be aware of the power-status of my laptop. If the power cord is plugged in, then KDM should start KDE 4 as usual, but if the laptop is relaying on its battery, then it should start KDE3 or some other light-weight environment of my choice.
What if you unplug your cable during the work? Idle KDE desktop on my new laptop uses ~4%, on old ~7% CPU. So KDE is not the problem there. Either disable desktop effects, either set low power usage CPU mode, but that is different story and this bug can be closed :)
That is not what I meant at all. If the laptop is in battery mode, then I want the battery to last as long as possible and thus use something lightweight like Enlightenment or Xmonad. I can always select the environment I want in the combo box, but if I'm using autologon, then I have to log out first. This is not a bug, but a "wish". If nobody thinks it's useful then close it by all means.
Yeah, auto log in might be a problem here. Have you made any measurements, how long does the battery lasts with KDE4 and with KDE3/xfce or similar? (best if both situations, in idle and loaded (browsing web, doing office work etc))
I haven't done any measurements yet. Nevertheless the idle "plasma-desktop" process sometimes uses 90% of the CPU for several minutes without any apparent reason. Other KDE applications (like Dolphin) are also pretty wasteful with the resources under certain circumstances. I don't want to care about all that and just use a different, minimalist environment that might not be as comfortable, but where my battery lasts.
KDM is unmaintained and not used in KDE Plasma 5. SDDM is the login manager used in KDE Plasma 5. If you still have this same issue with SDDM, please file an issue on the SDDM bugtracker (after doing a search for existing issues first!): https://github.com/sddm/sddm/issues/