PowerTop is tool that detects which Linux programsand kernel tunables are resulting in the largestpower consumption and use of battery time. Byfixing (or closing) these applications orprocesses, you can immediately see the powersavings in the tool. You'll also see the estimatedtime left for battery power if you are running alaptop.License: GNU General Public License (GPL)Changes:
On sufficiently new CPUs (and Linux kernel 2.6.25), Powertop now reports which C-states the CPU and BIOS report and support. Support for reading C-state information via sysfs was added. Support for sysfs power supply class was added. Support for the "P" key to show the PIDs of the processes when possible was added. Support for Intel 4965 wireless power saving mode was added. Powertop now shows USB suspend statistics as a low priority hint for busy devices and general USB suspend statistics in dump mode.

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