Laptop minimal power consumption tweaks [duplicate]

Question

I've recently installed Ubuntu 11.10 on a new Lenovo X220 laptop with a 9-cells battery. I have a trans-atlantic flight coming up, and I would like to use my laptop during it. Lenovo claims that this battery should last for a really long time.

How can I configure my laptop to consume minimal power? I didn't see any detailed power management panel in the system settings, so how to I tweak it?

Also, can someone report a tried-and-tested configuration? Performance is not an issue, since I'm going to use it for coding or reading during the flight, not for playing games of watching movies. Playing audio would be nice, but not a must.

Answer 1

Besides Powertop (available from Software Center), and turning all options to GOOD when on battery, you need to set several kernel parameters:

i915.i915_enable_rc6=1
i915.i915_enable_fbc=1
i915.lvds_downclock=1
pcie_aspm=force

Add to /etc/default/grub, Line starting with GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm i915.i915_enable_rc6=1 i915.lvds_downclock=1"

call sudo update-grub after editing...

This boosted my battery life from 4 hours to over 10 hours (without networking)

Check out this post http://www.williambrownstreet.net/blog/?p=387

Answer 2

The kernel team also has a Power Management tweaks page:

• https://wiki.ubuntu.com/Kernel/PowerManagement/PowerSavingTweaks

Answer 3

Here are things that I've tried that seem to work:

• Run PowerTop. For me, that revealed some stray gtk-gnash processes that didn't disappear even after I quit Firefox. So I did ps aux | grep "gnash" and killed those processes manually.

• Stop DesktopCouch, per Stop and start desktop couch with "service"?

• Stop UbuntOne Sync, via How can I stop ubuntuone-syncd?

I may also set up a "battery" compiz profile that has no bells and whistles and switch to that when I want to minimize compiz's power use.

Answer 4

I have found that logging into Unity 2d instead of 3d helps tremendously:

• How do I install and switch to the Unity 2D desktop?

Also from my personal experience, if you use Chrome/Chromium it consumes a bunch of power when compared to Firefox, so when I am in a battery situation I switch to Firefox. Also if you can get away with it, turning off Javascript in Firefox will also dramatically cut its power usage, though it's difficult to use most modern websites without Javascript.

Answer 5

Besides Jupiter try also Powertop (available in Software Center) - it's a console application which does two great things: 1) monitors power consumption 2) allows you to easily apply some little power tweaks.

Also check some info on the power regressions in recent versions of kernel, most notably issues with PCIe ASPM.

It's a good idea to use non-accelerated desktop environment, like Unity2D or Gnome Classic without compositing (no effects).

Answer 6

I also have a Thinkpad (T410) and discovered there's no silver bullet way.

Some of it is in your control. That is just being aware of all the systems that consume power and making sure that they're not being ravenous/performance maximizing. Here are a few steps I took. They made my laptop stop overheating to the point of powering down but there is still more to be done. Definitely make sure your BIOS is up to date (lenovo makes boot cds for it) is the biggest step of that list.

Having said that, there's also things taking power that are not apparently changeable. As you see in powertop's "Tunables" tab, there are a whole bunch of "Bad"s (power consuming processes and hardware) that it's not obvious if the end user can tweak them to become better.