Re: PowerTop on Debian Stretch

Guys, I am glad to tell you that my problem has been solved.

The problem was actually with my AMD GPU. Thank you Arian, for driving my attention on the GPU.

I followed the instructions on https://wiki.debian.org/AtiHowTo#Debian_Stretch_.28testing.29

and installed the missing firmwares and packages. After that I ran powertop --calibrate and then powertop --auto-tune.

I can now get a battery life of up to 6-7 hr on Debian 😁

What happened according to me was that PowerTop was not able to detect my AMD GPU as the required firmware was not installed. After installing the firmware, PowerTop was able to calibrate properly and take the correct measurements.

Richard Owlett wrote:

>Please note use of present tense.
>I see two possible interpretations:
> 1. he has a multi-boot installation. In which case he is NOW getting longer run
> times in Windows and Ubuntu than in Debian.
> 2. he did a clean install of Debian and saw an IMMEDIATE decrease in run time.

>If that is not so, I ask Mr. Gajadur to clarify.

Yes I actually have a dual boot installation. I first Dual booted Windows 7 and Debian 9. After finding that the battery life on Debian was only 3 hr, I replaced the Debian installation with Ubuntu 15.10 installation just to see how the battery life is on Ubuntu. I found that I could get a battery life of up to 5hr after using PowerTop on Ubuntu. However I am not a fan of Ubuntu. Debian is the only linux distro I love. So I removed Ubuntu and re-installed Debian and tried to find out what was causing the low battery life on Debian.

But now there is nothing to worry about as the problem has been solved thanks to Arian.

I want to thank you all for your comments and help 😀

Best Regards,

Dwijesh

On Wed, Feb 10, 2016 at 11:39 PM, David Wright <deblis@lionunicorn.co.uk> wrote:

On Wed 10 Feb 2016 at 11:32:48 (+0530), Jos Collin wrote:
> Hi, I'm not answering your question. But my suggestion is: don't bother about
> your battery life. Because even if you get 10 hours now, it is going to reduce
> slowly and reach 30 mins or 10 mins with in a few years. Then you have to
> replace your battery with a new one.
>
> I had a battery that drains to 0% with in 30 secs. I replaced that in 2012 with
> a 9 cell battery, when I started traveling with my laptop. The new battery also
> drains to 0% within 30 secs now.
>
> So I advice you to forget about battery life and move on to other important
> things. :-)

The (small size) battery on this laptop contains 42Wh fully charged.
Discharging it in 30 seconds would generate 5kW which is two
high-power electric kettles in the UK, over three in the US.

So either your battery hasn't charged properly, or else it's not
discharging properly, probably because there's a duff cell. In the
latter case, the battery remains a hazard because it still contains a
lot of charge if only it could find a discharge path.

> On 10-Feb-2016 11:05 AM, "Dwijesh Gajadur" <dwijesh1@gmail.com> wrote:
> I have a Dell Inspiron 5559 laptop which has a 40WHr, 4-cell battery. On
> Windows 7 I get a battery life of 6-7 hours. On Ubuntu I get a battery life
> of 5 hours after using PowerTop.
> However on Debian I get only 3 hours of battery life. I have done
> calibration several times and for several hours but I get only 3 hours of
> battery life.

If these timings can be achieved at will, I'd be interested to know if
the laptop was running at the same temperature on the various OSes. A
poor video driver might waste a lot of power. I suspect this is the
case with my own Dell laptop; given the chance it would make a cuppa.
I occasionally see the CPU at 96.5°C.

> My Question is, is it normal to get the lines:
> □ Cannot load from file /var/cache/powertop/saved_parameters.powertop
> □ Devfreq not enabled
> Is it because of these lines that PowerTop is unable to extend the battery
> life?
> Debian Stretch is currently using PowerTop version 2.8 and I heard
> somewhere on a forum that there is a bug in the 2.8 version. Is it true
> that there is a bug ? And is it that bug which is causing the problem?

Does https://bugs.debian.org/cgi-bin/pkgreport.cgi?dist=unstable;package=powertop help?

Cheers,
David.