Auckland Testing Summary 23 March 2013

Richard A. Smith richard at
Mon Mar 25 22:19:34 EDT 2013

On 03/25/2013 02:03 PM, Richard Smith wrote:
>>> Battery life on XO-4 C2 seems significantly improved over previous builds.
>>> We would be interested in a confirmation or otherwise of this in the power
>>> log analysis.
>> I guess you are comparing to 13.1.0 build 36?
>> The big difference here is that 13.1.0 build 36 has automatic power
>> management disabled, it is now enabled in 13.2.0 (not 100% stable just
>> yet, but we continue to shake out the bugs).
> Its probably the firmware change rather than a build specific change.
> We turned off unused cores and in q7b23 and that made almost 800mW
> worth of difference across the board in operational power draw.  I'll
> do a plot of your power logs though and confirm.

It appears there is considerable difference between your previous tests 
and now.  Last round of logs I have from you prior to this one was March 
2nd and prior to that was November 15, 2012 is that correct or did I 
miss a batch between November and March?

Here's a ploy of XO-4 only 13.1.0-32 vs 13.2.0-1 all your other XO-4 
13.1.0 builds I have were very early and not really interesting from a 
power standpoint.

Your peak decreased which I believe is from your firmware upgrade but 
does not explain the whole story.  A closer look at your log file shows 
a much, much higher suspend frequency in 13.2.  In your 13.1 tests you 
had perhaps 1 or 2 suspends whereas in the 13.2 log files almost every 
other line is a suspend event.

You didn't change your testing procedure did you?  Something that would 
allow for more idleness?

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

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