I'm using PowerTop v2.1 in Ubuntu 13.04 and I'm getting some pretty strange readings. I've already run powertop --calibrate too. The main screen reads this:

enter image description here

As you can see, the power estimates do add up to about 12.8W, perhaps a bit more. However, the device 'USB device: USB2.0-CRW (Generic)' is reporting a shocking 8.7W of usage. I believe this is the SD card reader on my laptop, I'd like to try to disable it but am not sure how.

But I'm also fairly certain this number can't be right - even at 100% usage I don't think it's going to use 8.7W, and there's no way that power hogs like wlan0 and chromium-browser and perhaps compiz are using less than 1W.

Can anyone offer their thoughts about what might be wrong and what steps I can take to reduce power usage and/or get PowerTop to report correctly?

  • Are you sure that you have --configure switch? Wouldn't that be --calibrate? – Braiam Aug 2 '13 at 19:45
  • You are correct, I just typed it wrong in the question. Edited. – Alex Aug 8 '13 at 15:21

You can instead generate an html report that will give you the basis to optimize your settings. Run:

 sudo powertop --html

It will generate an html inform, which will have an "Tunning" section with all the optimization you could do to your system:

enter image description here

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  • It didn't fix my problem but did give a bit more info. On the HTML it actually doesn't list the device as a power drain at all (as opposed to the command-line util), but the sum of the estimates (under 'Summary') is hardly 1W... also, under 'Device Info' it lists 0W power drain from the device in question. As for the 'Tuning' section, I'll keep troubleshooting but I don't think any of those features are responsible (they're alll activated, I can try deactivating some to see if that helps). It just seems to be reporting incorrect values. – Alex Aug 8 '13 at 15:32
  • @Alex it's either a bug, or your card lying. My system showed some devices using 100% (for some weird reason they didn't show the Watts) like the keyboard and mouse. Maybe powertop wouldn't be able to calculate correctly if the device lie – Braiam Aug 9 '13 at 5:09

I'm running same version of powertop as you I guess:

kreso@h17:~$ sudo powertop --version
PowerTOP versionv2.1, compiled on Aug 23 2012

and I do not have that option like you have --configure.. but I have this:

sudo powertop --calibrate

When you run it it will do a couple of test and optimizations for laptop to optimize the power usage on ports, display, cpu etc..

This one is my favorite:

enter image description here

and then try to run it again.. see if that helps,

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