PowerManagementASPM

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For power measurement, we currently recommend using the older version of powertop 1.13 as this clearly displays the ACPI estimated power consumption. A .deb for this can be found [[https://launchpad.net/~colin-king/+archive/powermanagement|here]. We recommend running powertop as follows:

 * Boot the machine, start powertop 1.13
 * Wait until you get an ACPI estimated power consumption value.
 * Gather 15 measurements (it is updated regularly).
 * Discard the 5 results.
 * Take average of the last 10 results.
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 * Run powertop for 10 minutes on an idle system and note power consumption  * Run powertop on an idle system and note power consumption
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 * Run powertop for 10 minutes on an idle system and note power consumption  * Run powertop on an idle system and note power consumption
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||Example||68ET27WW||64||3.1.0-2-generic||23W||3.1.0-2-generic||19W|| ||Lenovo 3000N200||68ET27WW||64||3.1.0-2-generic||24.3W||3.1.0-2-generic||25.4W||

ASPM PCIe Bug

As noted by Phoronix ASPM PCIe power saving has been problematic and a recent patch by Matthew Garrett has re-worked this to clear the ASPM state on all devices on a successful handoff of PCIe control to the OS.

We therefore are providing patched kernels carrying Matthew's fix for testing purposes only to see how well this works across a broad range of machines. Kernels can be found in:

For power measurement, we currently recommend using the older version of powertop 1.13 as this clearly displays the ACPI estimated power consumption. A .deb for this can be found [[https://launchpad.net/~colin-king/+archive/powermanagement|here]. We recommend running powertop as follows:

  • Boot the machine, start powertop 1.13
  • Wait until you get an ACPI estimated power consumption value.
  • Gather 15 measurements (it is updated regularly).
  • Discard the 5 results.
  • Take average of the last 10 results.

Testing procedure:

  • Ensure laptop is fully charged
  • Unplug AC power
  • Run powertop on an idle system and note power consumption
  • Plug in AC power
  • Install the new kernel containing the ASPM fix
  • Ensure laptop is fully charged
  • Unplug AC power
  • Run powertop on an idle system and note power consumption
  • Gather the BIOS version using: sudo dmidecode -t 0 | grep "Version:"
  • Add results to the table below:

Machine

BIOS

32/64 bit kernel

Original Kernel

Original Kernel Power

ASPM fix Kernel

ASPM fix Power

Lenovo 3000N200

68ET27WW

64

3.1.0-2-generic

24.3W

3.1.0-2-generic

25.4W

Kernel/PowerManagementASPM (last edited 2012-02-19 14:59:07 by costing)