Hi! I played a bit with acpi on my toshiba, and got following figures (toshiba satellite 4030cdt): system powered on, disk spinning, backlight on, low brightness 12.8W high brigtness +0.8W no backlight -4.8W while(1) loop +7.2W disk spindown -0.5W disk activity +2.1W Toshiba without backlight, idle cpu and disk spun down is 6.9W Toshiba doing kernel compile takes 22.3W That's quite a difference, and CPU (300MHz mobile celeron) seems to take quite a lot of power (even in while(1) loop), which in turn means that power managment is very important. BTW compare these numbers with philips velo handheld: 0.4W idle system, 0.6W with backlight, 1.3W system computing at max, <0.1W system with slowed down clocks. In this case, CPU is able to take as much power as the rest of system. ACPI seems to be much better at saving heat from CPU: it replaces idle loop and is able to conserve power pretty well. CPU seems to do 10x as much instructions with APM -- probably due to kapmd design. Pavel -- I'm [EMAIL PROTECTED] "In my country we have almost anarchy and I don't care." Panos Katsaloulis describing me w.r.t. patents at [EMAIL PROTECTED] ----- End forwarded message ----- -- I'm [EMAIL PROTECTED] "In my country we have almost anarchy and I don't care." Panos Katsaloulis describing me w.r.t. patents at [EMAIL PROTECTED] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/