<> Please help to improve this page if you have more tools or ideas to add. == Nexus7 Power Measurement == Steve Conklin did an initial investigation on the power consumption on the Nexus7 by watching the I2C bus and doing some disassembly of the unit: * [[attachment:nexus-power.odp|Initial Nexus7 Power Investigation (ODP)]] * git repo for tools mentioned in the above presentation: `git@github.com:sconklin/nexus-tools.git` (https://github.com/sconklin/nexus-tools) == Identifying Issues == The same tools used to identify power issues for other architectures (like powertop) work just fine: * [[Kernel/PowerManagement/IdentifyingIssues| Identifying Power Management Issues]] * Measuring CPU usage is a good way to detect when your application is drawing too much power, kcachegrind and callgrind (part of Valgrind) are excellent tools. == Statistics == Colin King maintains several tools to gather statistics on power consumption: * [[http://smackerelofopinion.blogspot.com.es/2011/12/monitoring-proctimerstats.html|Eventstat]]: calculates the rate of events per second and can dump the data in a .csv * $ sudo apt-get install eventstat * $ sudo eventstat == Hardware Tools == The ARM Energy Probe is a hardware tool that is fairly cheap and can be used to measure power consumption. It uses a GPL software stack and offers command-line and HTML5+websockets interface. Here is an intro video on using the [[https://www.youtube.com/watch?v=aDStdtopy_g|ARM Energy Probe]]. At Linaro Connect, Andy Green, from Linaro, gave a very good presentation on power measurement ([[attachment:slides.pdf|Slides on PDF]], [[http://www.youtube.com/watch?v=rTwqaKFiSNk|Youtube presentation]])