Impacts of disabling Automatic Power Management

Richard A. Smith richard at
Sat Feb 4 06:01:26 EST 2012

On 02/04/2012 12:13 AM, Sridhar Dhanapalan wrote:
>> What build are you basing your images off of?
> We're building from Dextrose 3, which is in turn based on 11.3.0.
> This version is still in development and hence isn't used in the
> field. I'm not sure how useful data from the currently-deployed OS
> (10.1.3) would be.

Its not as useful as it could be but its not useless.  There is a bug in 
10.1.3 where the time in suspend is not tracked correctly.

So from the logs we can tell how many times is suspended per second of 
run time but we can't tell the exact percentage of suspend time vs runtime.

Its still a place to start.  If you have lots of suspends/run time then 
you know that turning off aggressive suspend/resume will affect your 
battery life.  If you have few then it probably won't matter much.

Of course the ASR setting may not really matter.  Have you actually 
tested what your battery life is with the 3G modem connected up and the 
machine idle with ASR disabled?

I've heard that 3G modems suck quite a bit of power and USB itself sucks 
power.  With that extra load the savings you get from anything but a 
_lot_ of idleness may not really amount to much.

If you run a base line test then we can estimate what your life would be 
if for say you added 20% of idle suspend on top of that.

Richard A. Smith  <richard at>
One Laptop per Child

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