Arch Linux

Torain

Member

Registered: 2012-03-14

Posts: 2

Thinkpad T540P Power Consumption

Hello,

i have a little problem with  my T540p. I just can't get the power consumption under 17W in idle. I already use powersave and intel p_state and blacklistet nouveau to use the integrated graphics card (it's not possible to deactivate the nvidia in bios).
My Laptop has a 4700mq and a SSD so it should be possible to go down to at least 12W in idle i guess? Bluetooth is already deactivated.
My guess is that the nvidia card is still running even though it isn't used, is it possible to deactivate it on boot?

GSF1200S

Member

Registered: 2008-12-24

Posts: 474

Re: Thinkpad T540P Power Consumption

Hello,

i have a little problem with  my T540p. I just can't get the power consumption under 17W in idle. I already use powersave and intel p_state and blacklistet nouveau to use the integrated graphics card (it's not possible to deactivate the nvidia in bios).
My Laptop has a 4700mq and a SSD so it should be possible to go down to at least 12W in idle i guess? Bluetooth is already deactivated.
My guess is that the nvidia card is still running even though it isn't used, is it possible to deactivate it on boot?

Im guessing you are using powertop to gauge power consumption? Did you follow any of its recommendations? Im not sure on the 540, but on the 530 you can switch to "Integrated Graphics" under Display in the BIOS setup. Optimus also works on the 530, so its likely to work on yours as well. I notice you say you cant disable it- how do you know for sure? Can you try to setup optimus?

I have a T530. You need to setup laptop-mode-tools or tlp. What desktop environment or window manager do you use? Even setup with Openbox, Arch used over 14watts idle. I installed laptop-mode-tools first and tweaked away- eventually I got it down to about 6.5 watts. Then I installed tlp (making sure to bacman laptop-mode-tools first) and it immediately dropped to 6 watts

tlp is pretty much install and forget. However, you would be amazed at what some programs can suck up while youre just idling. Parcellite for instance used over half a watt; since I use xfce4-panel on Openbox, I switched to xfce4-clipman which uses next to nothing. Compositing (kde's compositor, gnome 3, xfwin's compositing, or compton) is very expensive even if it only uses your Intel card- when on battery, disable compositing completely.

Also, just a heads up- you need to help us help you. You need to give us details on hardware, give us print outs of powertop (in code tags), lspci, lsusb, etc etc...

Last edited by GSF1200S (2014-05-29 16:56:10)