Impacts of disabling Automatic Power Management

Richard A. Smith richard at
Wed Feb 1 17:09:13 EST 2012

On 01/31/2012 11:43 PM, Paul Fox wrote:
> sridhar wrote:
>   >  We are considering disabling Automatic Power Management because of its
>   >  impact on collaboration and 3G connectivity.
>   >
>   >  What kind of battery life can we expect from an XO-1.5 with Automatic
>   >  Power Management disabled as opposed to enabled? I understand that
>   >  this can vary wildly with usage, but is there an average estimate?
> he's on a very long plane flight, but i'll try and channel richard:
>      "it depends."
> how did i do?  :-)

You have learned well.

Sirdhar:  Unfortunately theres no way we can answer your question ( or 
even make a SWAG) without known how much idleness is in your normal 
workload.  Automatic Power Management only makes a big difference if 
there is a lot of time spent idle.  If you are running Tam-Tam the 
entire time then turning off aggressive suspend/resume will make zero 

powerd tracks this though so if you can collect some powerd logs from 
some of your users then we can make a guess at figuring out what your 
impact will be.

powerd logs are located in the ~olcp/power-logs directory.  Copy all the 
files in there off of several machines that have been used in the 
classroom and send them to me and we can take a look at what sort of 
profile you have.

What build are you basing your images off of?

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

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