[maemo-users] Battery Life

From: Eero Tamminen eero.tamminen at nokia.com
Date: Fri Aug 17 11:54:09 EEST 2007

ext Frantisek Dufka wrote:
> True. But still seeing power consumption could help and having actual
> current drawn from battery somewhere in /proc would be very useful in
> many situations.
> Even if I agree with things you said I still think your response is
> influenced by the fact that Nokia hides such values from us (either
> because it is not possible due to current hw design or because it thinks
> such information is sensitive).
> I had iPAQ 3870 and there was such value available. It helped me a lot
> (both as user and programmer) to understand what is the cost of having
> some features enabled (playing audio, brightness on higher level,
> bluetooth communication, cpu busy, reading from card, ...).
> Things are not black and white. Maybe sometimes something doesn't need
> to be done. If you know the costs you may avoid some features or try to
> optimize its usage in your application. If you don't know the
> consumption then you can't optimize (both as user and developer).
> Examples of such optimizations:
> It is worthwhile to implement caching network data to mmc card while
> playing media (i.e. read playlist ahead as fast as possible from
> network) or is streaming on demand good enough?
> Does the brightness consumes as much as I expect?
> How much do I save when turning volume down?
> Does black theme save power?

AFAIK no (unless you mean switching the display off :)).  Igor?

> These were just examples and some of them may not be good but you should
> still see the point.

Yes, they are good points.  Better tools are always needed.

I'm just frustrated that people don't use the tools that
are already available, both on desktop[1] and for the device.
Even with the currency consumption meter you would still need top &
strace to find out which process actually consumes the power.

It's not necessary that the application developers themselves use the
tools (they are busy developing their applications), but the (power :))
users can use these tools also.

	- Eero

[1] E.g. gnome power manager was something horrible when I last
straced it on Ubuntu, it was constantly polling... I later noticed
that it was mentioned also on the powertop page.

More information about the maemo-users mailing list