PowerManagementASPM

Revision 33 as of 2011-11-14 17:49:08

Clear message

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 powertop-1 can be found here. We recommend running powertop as follows:

  • Boot the machine, start powertop-1
  • Wait until you get an ACPI estimated power consumption value.
  • Gather 15 measurements (it is updated regularly).
  • Discard the first 5 results.
  • Take average of the last 10 results (total/10)

Testing procedure:

  • Ensure laptop is fully charged
  • Unplug AC power
  • Run powertop-1 on an idle system and note power consumption
  • Plug in AC power
  • Install the new kernel containing the ASPM fix
  • Restart laptop and choose the new kernel
  • Ensure laptop is fully charged
  • Unplug AC power
  • Run powertop-1 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:

Please try and keep table in sorted order on the machine name. Thanks!

Machine

BIOS

32/64 bit kernel

Original Kernel

Original Kernel Power

ASPM fix Kernel

ASPM fix Power

Notes

Acer Aspire AO722

JE10BZ V1.04

64

3.0.0-12-generic

11.43 ± 0.39

3.0.0-13-generic

21.31 ± 0.2

Dell Latitude D620

OTD761 A02

32

3.0.0-12-generic

22.27 ± 1.13

3.0.0-13-generic

16.92 ± 0.99

Dell Latitude E6510

A03

32

3.0.0-13-generic-pae

18.06 ± 1.13

3.0.0-13-generic-pae

16.92 ± 0.99

Dell Vostro 3450

Version: A07

32

3.0.0-12-generic-pae

20.45

3.0.0-13-generic-pae

19.55

Dell Inspiron 6400

A13

64

3.1.0-2-generic

23.3W

3.1.0-2-generic

23.2W

Dell Inspiron N4010

A13

64

3.1.0-2-generic

1.21W

3.1.0-2-generic

0.95W

1

Dell Studio 1558

A12

64

3.0.0-13-generic

2.22W

3.0.0-13-generic

1.8W

1

HP Mini 210

F0.2

64

3.0.0-12-generic

14.3W

3.0.0-13-generic

8.7W

HP Mini 210

F0.4

32

3.1.0-2-generic

11.3W

3.1.0-2-generic

11.7W

HP ProBook 5420s

68AZZ Ver. F.0F

64

3.0.0-12-generic

25.06W

3.0.0-13-generic

25.66W

Lenovo 3000N200

68ET27WW

64

3.1.0-2-generic

24.3W

3.1.0-2-generic

25.4W

Lenovo IdeaPad S12

19CN1AWW

32

3.0.0-13-generic

10.65W

3.0.0-13-generic

10.67W

2

Lenovo Thinkpad T420s (i915.i915_enable_rc6=1)

8CET46WW (1.26)

64

3.1.0-2-generic

12.29W

3.1.0-2-generic

9.14W

Lenovo Thinkpad T510

6MET84WW (1.44)

32

3.0.0-12-generic-pae

16.03W

3.0.0-13-generic-pae

14.01W

Lenovo Thinkpad T60

79ET62WW (1.07)

32

3.0.0-13-generic

22.17W ± 0.38W

3.0.0-13-generic

22.19W ± 0.36W

Lenovi Thinkpad X220

8DET41WW (1.11)

64

3.0.0-13.generic

21.4

3.0.0-13.generic

19.9

Lenovo Thinkpad X301

6EET54WW (3.14 )

64

3.1.0-2-generic

11.4W

3.1.0-2-generic

11.4W

Lenovo Thinkpad X301

6EET44WW (3.04)

64

3.1.0-2-generic

10.4W

3.1.0-2-generic

10.4W

ACER Aspire One 533

V1.05

32

3.0.0-13-generic

7.58W

3.0.0-13-generic

7.7W

2

Notes:

  1. It is probabal that these machines are incorrectly reporting power such that the value is reported as 1/10th of the actual.
  2. This variance (up) is likely within the accuracy of the figures for this machine.