Sorry, you need to enable JavaScript to visit this website.


Your feedback is important to keep improving our website and offer you a more reliable experience.


This Linux utility implements a software power meter which uses Intel® RAPL (Running Average Power Limit) driver using power capping sysfs.  Intel® RAPL driver and the Linux Power Cap sysfs are available in the Linux kernel 3.13 release.

Make sure that the kernel configs "CONFIG_POWERCAP" and "CONFIG_INTEL_RAPL" are enabled in your kernel; you can verify by checking for the presence of a folder:


  --help Display this usage information
  --version Show version
  --no-daemon No daemon
  --index.html specify local index.html path

By default RAPL power meter starts as a Linux daemon; it can be disabled by specifying no-daemon mode.   The default port is :9999, though this can be changed on the command line option.

This program binds to localhost unless an interface is specified via command line option.

There is a default index.html built into this program, which can be changed by command line option (a sample is provided for reference).  The command line option hostname can be used to specify server path in index.html. Some proxies expect domain names in the hostname to route requests.

This utility allows "read only" access to power capping sysfs, so no root privilege is required.

RAPL starts a mini http server and waits for "GET" requests. Each "GET" request can have one of the following paths:


     Returns number of power cap domains present.   Each domain is an independent power unit, where power can be measured.


Domains are organized in a hierarchical model.  A domain can contain multiple sub domains.  Refer to documentation of Linux Power Cap sysfs under kernel tree documentation.


     Returns domain energy.  The path follows same model as rapl_domain_name.


     Returns maximum possible energy. The path follows same model as rapl_domain_name.

Default index.html
The default web page uses http GET requests to calculate power and display. It calculates power for all available domains and sub domains, displaying the results in a table which is updated inline with JavaScript and AJAX requests.  The logging feature, when enabled, logs all power activity and allows for download of log data in a CSV format.

v1.0 : Base release