PM utils power saving improvements - call for testing

[Eric Miao]

On Tue, Dec 13, 2011 at 11:15 PM, Colin Ian King
<colin.king at canonical.com> wrote:
> Hi there,
>
> == Call for testing: pm-utils power saving improvements ==
>
> PM utils power.d scripts control power management settings when a laptop is
> on mains or battery power. The power.d scripts currently attempt to optimize
> power savings when on battery power by adjusting settings such as audio and
> wireless power management, readahead and journal commit settings to name
> just a few.
>
> The kernel provides mechanisms to put specific USB and PCI devices into
> lower power consuming states and with careful choice of the specific devices
> we can reduce the overall system power consumption by a few Watts depending
> on the types of devices installed on a laptop or netbook.
>
> Initial analysis on a range of hardware has identified a set of devices
> (Bluetooth, Wireless, Ethernet, SD card readers) that can be put into a low
> power state and we are looking for volunteers to test some updated pm-utils
> power.d scripts. We are interested in two types of test:
>
> 1) Do these pm-util scripts save any power across a range of machines?
>
> 2) Does enabling these savings affect any device behavior?
>
> A crowd-sourcing testing Wiki page has been created that describes how to
> test these updated pm-utils scripts and can be found at:
>
> https://wiki.ubuntu.com/Kernel/PowerManagementPMUtils

Great work, Colin!

I've updated the page with test on my HP Pavilion dm1, an AMD E-350
netbook. It did improve, the result of 1st trial, however, seems not
very consistent which I don't know why.

1st trial:

BIOS  :  F.12
Kernel:  Linux pavilion-dm1 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2
13:25:36 UTC 2011 i686 athlon i386 GNU/Linux
Power consumption BEFORE using new pm-utils power.d scripts:
  5.87 Watts on Average with Standard Deviation 0.25

Power consumption AFTER using new pm-utils power.d scripts:
  5.86 Watts on Average with Standard Deviation 0.27

2nd trial:

BIOS  :  F.12
Kernel:  Linux pavilion-dm1 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2
13:25:36 UTC 2011 i686 athlon i386 GNU/Linux
Power consumption BEFORE using new pm-utils power.d scripts:
  7.85 Watts on Average with Standard Deviation 0.74

Power consumption AFTER using new pm-utils power.d scripts:
  7.76 Watts on Average with Standard Deviation 0.76

3rd trial:

BIOS  :  F.12
Kernel:  Linux pavilion-dm1 3.0.0-13-generic #22-Ubuntu SMP Wed Nov 2
13:25:36 UTC 2011 i686 athlon i386 GNU/Linux
Power consumption BEFORE using new pm-utils power.d scripts:
  7.82 Watts on Average with Standard Deviation 0.44

Power consumption AFTER using new pm-utils power.d scripts:
  7.74 Watts on Average with Standard Deviation 0.12