Overview

PowerJoular is a command line software to monitor, in real time, the power consumption of software and hardware components, across multiple platforms and virtual machines.

PowerJoular is part of the project.

PowerJoular can monitor the power consumption, in real time, of the CPU and the GPU in general, and also for a specific application (through its name or PID). It works on Linux, Windows, macOS and FreeBSD, on multiple architectures (x86_64, ARM) and devices (computers, servers, Macs, Raspberry Pi, etc.).

The official website of PowerJoular is: https://www.noureddine.org/research/joular/powerjoular.

Features

• Monitor power consumption of CPU and GPU of PC/servers
• Monitor power consumption of Macs, Apple Silicon and Intel
• Monitor power consumption of Raspberry Pi and Asus Tinker Board devices
• Monitor power consumption inside virtual machines
• Monitor power consumption of individual applications or processes
• Expose power consumption to the terminal, CSV files, and a shared memory ring buffer
• Provides a systemd service (daemon) to continuously monitor power of devices on Linux
• Low overhead (written in Ada and compiled to native code, one binary with nothing to install alongside it)

What changed in version 2

Version 2 does the measuring using two Ada libraries we developed, Joular Core and CPU Load, instead of its own code. This also brings Windows, macOS and FreeBSD support, and AMD graphic cards (Nvidia cards are now read through NVML instead of nvidia-smi).

• New: -r writes the power data to a shared memory ring buffer.
• Removed: -k, which measured a process from its threads. It was experimental, and the process readings no longer need it.
• Removed: -l, which picked the linear power models of the single-board computers. The polynomial models are now the only ones used, as they are much more accurate and their overhead is minimal.
• Removed: -c, which wrote the timestamps in milliseconds.

Other main differences:

• The CSV files start with a Unix timestamp in seconds instead of a date and time, and hold four digits after the dot instead of fourteen. The columns and the header have been renamed, with Timestamp and CPU Usage.
• The terminal no longer shows the difference of power consumption from the last metric, and Ctrl+C no longer prints the total energy consumed.
• On Linux, the CPU power is the RAPL package domain only. Version 1 used the Psys domain when there was one, or added the DRAM domain to the package, so the values can be lower than with version 1.
• The energy a RAPL processor reports is divided by how long the cycle actually took, rather than assumed to be exactly one second. On a busy machine where a cycle takes longer than one second, the watts reported are now the watts drawn.
• A file that cannot be written to, or a ring buffer that cannot be opened, is reported once and the monitoring continues. A power source that stops answering reads 0 until it answers again.
• The systemd service writes to /run/powerjoular/powerjoular-service.csv instead of /tmp, and runs with reduced privileges.

Cite this work

To cite our work in a research paper, please cite our paper in the 18th International Conference on Intelligent Environments (IE2022).

• PowerJoular and JoularJX: Multi-Platform Software Power Monitoring Tools. Adel Noureddine. In the 18th International Conference on Intelligent Environments (IE2022). Biarritz, France, 2022.

@inproceedings{noureddine-ie-2022,
  title = {PowerJoular and JoularJX: Multi-Platform Software Power Monitoring Tools},
  author = {Noureddine, Adel},
  booktitle = {18th International Conference on Intelligent Environments (IE2022)},
  address = {Biarritz, France},
  year = {2022},
  month = {Jun},
  keywords = {Power Monitoring; Measurement; Power Consumption; Energy Analysis}
}

License

PowerJoular is licensed under the GNU GPL 3 license only (GPL-3.0-only).

Copyright (c) 2020-2026, Adel Noureddine. All rights reserved. This program and the accompanying materials are made available under the terms of the GNU General Public License v3.0 only (GPL-3.0-only) which accompanies this distribution, and is available at: https://www.gnu.org/licenses/gpl-3.0.en.html

Author : Adel Noureddine