Arch Linux

vn14

Member

Registered: 2013-03-16

Posts: 4

Powertop reporting 100% PCI device usage, and poor battery life

I have Arch running on an HP Pavillion g4-1200tx laptop with these specs:

2.2 GHz Intel Core i3-2330M 3 MB L3 cache
4 GB 1333 MHz DDR3 Memory
AMD Radeon HD 6470M (1 GB DDR3 dedicated)

A vanilla install of Arch eats up the battery at around 28 watts.

After doing some power tweaks, mainly

• Installing and configuring tlp

• Activating the i915_enable_rc6

• Disabling the discrete GPU with vgaswitheroo

and with the wifi/bluetooth radios off and cpu scaled to powersave, it consumes 20 watts and is uncomfortably hot.

Powertop reports stats as follows:

I think this is because the PCI devices are at 100% use. But PCI runtime power mgmt. is active through tlp. I've tried laptop mode tools but tlp comparitively gives better results.
Here is the tlp stat output.

What should I do to improve the battery life and make it run cooler?

Last edited by vn14 (2013-05-01 12:52:30)

vn14

Member

Registered: 2013-03-16

Posts: 4

Re: Powertop reporting 100% PCI device usage, and poor battery life

bump?

mau5kito

Member

Registered: 2013-05-11

Posts: 6

Website

Re: Powertop reporting 100% PCI device usage, and poor battery life

Are you sure your discrete GPU is really disabled? I don't have a Radeon so I don't know much about that, but I had a similar problem with my GeForce so maybe it comes from there.

I don't think this is because of the PCI devices. Mine are all at 100% use in PowerTOP too.

Last edited by mau5kito (2013-05-13 09:32:08)

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vn14

Member

Registered: 2013-03-16

Posts: 4

Re: Powertop reporting 100% PCI device usage, and poor battery life

Oh! I thought it was so because PCI was at 100%.

The GPU is disabled.

# cat /sys/kernel/debug/vgaswitcheroo/switch 
0:DIS: :Off:0000:01:00.0
1:IGD:+:Pwr:0000:00:02.0

Also, it's not a desktop environment's fault (I'm running KDE); Same amount of power is consumed even when X is not running.

Is there a way to find out why the power consumption is so high?
How much power does Arch consume normally?

Last edited by vn14 (2013-05-16 13:14:37)