[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-devel
Subject:    Re: [PATCH] powerdevil-remove-cpufreq.patch
From:       Holger Macht <holger () homac ! de>
Date:       2010-03-08 13:39:31
Message-ID: 4B94FE13.2060403 () homac ! de
[Download RAW message or body]

On 03/08/2010 02:35 PM, Valerio Pilo wrote:
> In data lunedě 8 marzo 2010 14:16:38, Sebastian Kügler ha scritto:
> : > On Monday 08 March 2010 13:50:19 Valerio Pilo wrote:
>>>> It's a misunderstanding that you reduce energy consumption by setting
>>>> your processor's governor to 'powersave', really.
>>>>
>>>> Do you have numbers that you're battery lasts longer than before?
>>>
>>> Yes, it lasts longer. Not an amazing amount of time more, but still quite
>>> a  bit longer than when I put it into 'ondemand' and do usual work (web
>>> development and/or compiling stuff). This is keeping in mind screen
>>> brightness etc.
>>> I think it happens because when in 'powersave' mode, it can never run at
>>> full  speed...
>>
>> What numbers are we talking about? Is the machine completely idle when
>> measuring? If not, what are the workloads, are they comparable?
>>
> 
> uhm I can't *prove* it at the moment, since I'm at work, it's empirical 
> observation. The machine is not idle, I just unplug, set the 'extreme 
> powersave' profile (or leave the default powersave profile when I forget to 
> change it), raise the brightness up 3 notches (of ~12), then keep using kate 
> and firefox (typical web development) until the battery almost dries out.
> 
> I simply noticed i could get some more battery life with "extreme powersave", 
> rather than simply "powersave", at the same screen brightness. Quantifying 
> exactly that difference is out of my possibilities at the moment, sorry.

Ok, so you're not only changing the CPU frequency scaling policy but
rather a whole profile which might do other things, too. Didn't check
which, but this of course can have some impact on battery runtime. It's
interesting if there's prove if just and only changing the CPU freq
governor from ondemand to powersave gives you a lower power consumption.

Regards,
 Holger
 
>> Visit http://mail.kde.org/mailman/listinfo/kde-devel#unsub to unsubscribe <<

[prev in list] [next in list] [prev in thread] [next in thread]