Power management on g4's

Hi, I'm running opensuse 10.1 on a small cluster of G4's. The cluster is used only for computation, so I've removed monitors, keyboards etc and have the machines sitting on a shelf. Are there additional powersaving measures I can enable? Will linux put the machines into a "sleep" mode in a way similar to OSX if there are no cpu-intensive processes running? (I notice that the cooling fans never seem to spin down and am guessing that everything is running full-bore). Would pulling the graphics cards, disconnecting zip, cdrom drives etc reduce the electrical load substantially? Nathan Moore