Reduce Power Usage with PowerTOP

PowerTOP is a Linux tool created by Intel to identify software which causes increased power consumption even while your system is not working. By running PowerTOP and removing software which wakes your computer’s CPU from it’s idle state, you can increase the battery life of your laptop.

Install PowerTOP from the package powertop (click the link to install), or by running the command below in your terminal:

sudo apt-get install powertop

PowerTOP is a text-based application. Open a terminal and run this command to start it:

sudo powertop


Powertop will monitor your system for five seconds to gather information before starting.

The top left section of the interface shows the different CPU states, and how long your CPU was in each one. You want your CPU to use the highest C state (sleep state) as much as possible to save energy.

The top right section of the interface shows the different frequencies that your CPU supports (P-states). Your CPU should be using the lowest frequency available while it is idle to save power.

The line highlighted red shows the wakeups-from-idle per second number. Wakeups-from-idle per second shows you how often the CPU is woken up from idle by the processes on your system. You want this to be as low as possible to conserve power.

The top causes for wakeups list is the most important part of PowerTOP, it shows which processes are preventing your system from saving power. The lines shown in bold are the ones PowerTOP thinks are the most important.

Suggestions for reducing wakeups (and therefore saving power) are shown the the bottom of the window. There should be a shortcut key to temporarily apply the suggestion shown below.

To use less power, take PowerTOP’s suggestions and analyze the top causes for wakeups list and decide if you can disable some of the software or hardware on the list.

The top causes for wakeups on my Eee PC 901 running Ubuntu are the Bluetooth radio (BT-253), sound (HDA Intel), and WiFi radio (ra0). These account for about 85% of the wakeups. Initially I was getting about 170 wakeups/sec, and about 150 wakeups/sec after applying two suggestions that PowerTOP offered for the system.

[update] Commenter vor has linked to a guide he wrote on improving battery life, which includes setting up a script which runs when the power state changes. This script can be used to more permanently implement PowerTOP’s suggestions.

Archived Comments


Where could that command be put (i.e. echo 1500 > /proc/sys/vm/dirty_writeback_centisecs), if we wanted it to run at every boot?



Oh my good, first had about 1000 wake-ups, than stopped pidgin and it was down to 250! Such a hungry app.
Nvidia proprietary driver takes a lot too.

Ali Servet Dönmez

Nice tip! Thanks…


I bet this would be even more useful for people if you described how to implement them whenever on battery power. The problem with just using the powertop application is that the settings are lost when you restart. Since it’s mainly used to save power on battery, a brief guide/example of how to get certain settings whenever you start-up or whenever you go on battery power would be a beneficial addition to this. Just my 2 cents though.



Is this meant only for Intel systems or will it work on AMD as well.

[I have AMD Turion X2]


@flow: to reduce nvidia driver wakeups just put
Option “OnDemandVBlankInterrupts” “true”
in the device section of your your /etc/X11/xorg.conf .
In latest driver releases I’ve seen an option to do it on nvidia-settings configuration panel too.


Tom, I see on the screenshot that you also get the message:
no acpi power usage estimate available

I get the same on my acer 3002WTMI and I don’t know why powertop doesn’t show the W/h.
With my old thinkpad x40 everything worked well.
you can copy and paste every suggestion powertop gives you on a shell script and run it at boot (not suggested: you may be on AC power) or when ACPI detects the battery unplug.


Charles: I suppose you need to run it only once, as it seems to add an entry to a config file.


Can I use this with an AMD processor?


There are several related guides on the Ubuntu forums that I wrote (they address some of the above comments):


Manish: AMD processors should work with PowerTOP, but I don’t have an AMD system to test it with.


PowerTOP seems tailored to the Linux Kernel, not to a specific processor vendor. (thumbs up to Intel!) I gave it just a brief go yet, but it worked flawlessly thus far on my AMD64 laptop.



I tried Powertop and it suggested I disable the hal probing of my CD ROM device by using
hal-disable-polling –device /dev/cdrom
Now I have a lot of problems with my optical drive and I would like to undo this. Could you give me a hand?



Just reboot your system - PowerTOP’s suggestions are only applied temporarily.

Marconi Poveda

Hi Tom,

I have the same problems of Anonymous :( and don’t know how to revert it.

I can’t not mount more than one CD by time, if I need to mount another I must reboot my computer, I can’t remember if it’s the same option Anonymous disable I just can remember it was about auto mounting CDs.

Can you please help me to revert the efects? Should remove powertop helps?



Marconi Poveda:
Rebooting your system should revert the changes, but if not, here’s a command that should:

sudo hal-disable-polling –enable-polling –device /dev/cdrom


That addresses several of my concerns autcally.

Respond via email