Liunx power consumption on laptops -- Enormous progress in the last few months

[Arjan van de Ven <arjan@linux.intel.com>]

Hi,

with all the tickless and other goodies going into the kernel in the 
last few months, there is a lot of hope that this helps Linux reduce 
power consumption... and the good news is that it does... once you fix 
some bugs and fix a bunch of userspace applications.

While it's hard to show "one size fits all" number/percentage, we took 
a bog standard Lenovo T61 laptop (no vendor preference, they just were 
the first one to deliver a model with the latest Intel chipset to our 
cubes) and measured the effect. The baseline we used was a 32 bit 
Fedora 7 installation; note that this already has the tickless kernel, 
but is lacking several of the key bugfixes that came afterwards.

We've put our measurements in a graph at

http://ww.linuxpowertop.org/results.php

With kernel fixes and features, the power consumption of this laptop 
went from 21.06 Watts to 18.25 Watts; with 2 additional userspace 
fixes the power consumption ended up at 15.5 Watts.

(Don't worry that this is the end of it; there's more stuff in the 
various project pipelines, and we'll keep measuring the progress over 
time)


All in all, personally I'm very happy to see Linux making such a huge 
step forward with tickless and can't wait for this step to be 
available in all distros and for all architectures...

Greetings,
    Arjan van de Ven