[maemo-developers] QT map widget

[From: Ian Stirling]

Till Harbaum / Lists wrote:
> Hi,
> 
> Am Samstag 12 Juni 2010 schrieb Joerg Reisenweber:
>> It's rather moot, as this isn't a movie at 25fps, so an occasional image 
>> refresh, no matter how it's done, will take magnitudes less energy per time in 
>> average, than the backlight eats to display the image. When screen is dimmed 
>> (or the widget invisible/hidden/background) then of course all gfx workload 
>> should suspend, for obvious reasons
> 
> 100% CPU load is bad no matter if this is for a 25fps movie or a 0.5fps 3d map
> widget. Believe me, i have these discussions regarding maep. People _do_ care
> for CPU load and battery consumption. And this is good.

I believe the point is not that battery life is unimportant, but that 
with the backlight on, the CPU using 200% of nominal for 2/25th of the 
time, this increases the total CPU power by 8%.

But - using numbers from 
http://wiki.maemo.org/N900_Hardware_Power_Consumption - with the screen 
on dim, and the GPS on, this 8% drops to 4% of total system load. - with 
the backlight on bright, it's only an increase of 2.5% or so.

The main point I was attempting to make was not this one anyway.

It was that while 3D may be possible on platforms similar to the n900, 
it is undesirable, even if it performs perfectly, if the widget may also 
be wanted to run on the increasing number of low end phones that may 
have limited or no 3D capability.

(Unless of course it can also do 2D optimally - but that seems like lots 
more code/work.)