All, I've been experimenting on enabling the hidden hpet on an ICH3-based system (Dell Latitude C640 P4 Mobile) using Thomas Gleixners patches [1]. My results are based on patching the Ubuntu 2.6.22-9 kernel.
Power usage (in Watt) Kernel Idle Tweaked Idle Full CPU Load 2.6.20-15-generic 34 - 60 2.6.22-ubuntu 34 32 60 2.6.22-ubuntu-hpet 34 32 60 As you can see from the result, no net gain is to be seen at all. All tests were measured with an external watt-meter without any batteries attached. The tweaked idle field wattage is acheived by activating all suggestions given by the powertop software. The only option that gave an actual reduction in the power consumption was "Disable Wifi Radio". The options activated were: Increased writeback time NMI Watchdog AC97 Powersave on Disable Wifi Radio [1] http://www.tglx.de/projects/hrtimers/ With kind regards Erik Andrén _______________________________________________ Power mailing list [email protected] http://www.bughost.org/mailman/listinfo/power
