[Olpc-open] kill-a-watt readings

[Sameer Verma]

I got hold of a Kill-a-watt unit today. This thing plugs into a power 
outlet and has a power plug on it which is where you plug in the device 
that draws power. Got it? :-)

http://www.p3international.com/products/p4460.html

Build 656, G1G1 laptop

XO turned off, empty battery: 21 watts
XO turned on, empty battery: 21 watts
XO turned on, battery removed: 10 watts (stays fairly steady during boot up)
XO turned on, battery removed, backlight turned off: 7 watts
XO turned on, battery removed, backlight turned off, camera+mic on: 8 watts

These readings are taken at the wall charger (Kill-a-watt says the wall 
charger is drawing 124 V) so there will be losses along the way 
(Richard's readings (http://wiki.laptop.org/go/XO_Power_Draw) are from 
the battery, so they are closer to the machine) but its interesting to 
see what's being pulled in at the wall socket.

For comparison, my Sony VAIO VGN-S380 
(http://computers.pricegrabber.com/laptop/m/7624589/details/st=product_tab/) 
has the following stats.

VAIO turned off, empty battery:  24 watts
VAIO turned on, empty battery:  50 watts
VAIO turned on, battery removed: 43 watts (39 to 43 watts during boot up)
VAIO turned on, battery removed, backlight turned to minimum: 23 watts
VAIO turned on, battery removed, backlight full, fan turns on (processor 
jumps from 800MHz to 1.73GHz): 71 watts


cheers,
Sameer

-- 
Dr. Sameer Verma, Ph.D.
Associate Professor of Information Systems
San Francisco State University
San Francisco CA 94132 USA
http://verma.sfsu.edu/
http://opensource.sfsu.edu/