How to use the command powerstat (with examples)

Powerstat is a command-line tool that allows users to measure the power consumption of a computer that has a battery power source or supports the RAPL interface. It provides various options to customize the sampling interval and number of samples, as well as additional statistical data.

Use case 1: Measure power with the default settings

Code:

powerstat

Motivation: This use case is useful when you want to quickly measure the power consumption of your computer without specifying custom settings. The default settings of 10 samples with an interval of 10 seconds provide a decent balance between accuracy and execution time.

Explanation: The command powerstat without any additional arguments will measure the power consumption using the default settings: 10 samples with an interval of 10 seconds.

Example output:

Consecutive Measurements (10 second interval)
Power measurements unavailable on this machine

Use case 2: Measure power with custom settings

Code:

powerstat interval number_of_samples

Motivation: Sometimes, you may want to adjust the interval and number of samples according to your specific needs. This use case allows you to do so by providing custom values.

Explanation: By specifying the interval and number_of_samples arguments, you can customize the frequency and duration of power measurements. The interval argument specifies the time in seconds between consecutive measurements, while the number_of_samples argument defines the total number of measurements to be taken.

Example output:

Consecutive Measurements (5 second interval)
Statistics:         126.42±0.15 W at 5% confidence

Use case 3: Measure power using Intel’s RAPL interface

Code:

powerstat -R interval number_of_samples

Motivation: Intel’s RAPL (Running Average Power Limit) interface provides more accurate and detailed power measurements on compatible systems. This use case allows you to take advantage of the RAPL interface by enabling it with the -R option.

Explanation: The -R option tells powerstat to use Intel’s RAPL interface for power measurements. This interface provides more accurate and detailed data on systems that support it.

Example output:

Consecutive Measurements (10 second interval)
Stats: 4.48% CPU use, 184.58±0.05 W at 5% confidence

Use case 4: Show a histogram of the power measurements

Code:

powerstat -H interval number_of_samples

Motivation: A histogram can provide a visual representation of the power consumption distribution, allowing you to observe any patterns or anomalies in the readings. This use case is helpful when you want to analyze the power consumption in a more visual way.

Explanation: The -H option enables the generation of a histogram of the power measurements. The histogram shows the distribution of power values over the measurements taken.

Example output:

Consecutive Measurements (10 second interval)
Histogram:
      123 | *
      126 | ***
      129 | ********
      132 | ****
      135 | ****
      138 | ***

Use case 5: Enable all statistics gathering options

Code:

powerstat -a interval number_of_samples

Motivation: Enabling all statistics gathering options provides more comprehensive information about the power consumption, including CPU utilization, energy usage, and additional statistical analysis. This use case is beneficial when you need detailed insights into the power usage of your system.

Explanation: The -a option enables all statistics gathering options available in powerstat. This includes CPU utilization, energy usage, standard deviation, and confidence interval calculations.

Example output:

Consecutive Measurements (10 second interval)
Stats: 4.48% CPU use, 184.58±0.05 W at 5% confidence
Energy full-drain duration: 8 hours 11 minutes (estimated)

Conclusion:

Powerstat is a versatile command-line tool for measuring power consumption on computers with battery power sources or RAPL interface support. By using the various options and arguments provided by powerstat, you can customize and gather detailed information about your system’s power usage. Whether you need a quick power measurement or a comprehensive statistical analysis, powerstat has got you covered.