Shell Auto-ASPM

Now with 50% less dependencies!

Requirements

• Linux system (any distribution - tested on Alpine, Debian and Arch)
• Root privileges (sudo access)
• pciutils installed (lspci, setpci commands)

  # Install on Ubuntu/Debian:
  sudo apt install pciutils
  
  # Install on RHEL/CentOS/Fedora:  
  sudo dnf install pciutils

Quick Start

# 1. Make script executable
chmod +x autoaspm.sh 

# 2. Optional: Preview what will be changed (safe, no modifications)
sudo ./autoaspm.sh --dry-run

# 3. Apply ASPM settings
sudo ./autoaspm.sh

Frequently Asked Questions

Q: Why not just use AutoASPM from Wolfgang?

A: There is nothing wrong with the python autoaspm script but I try to avoid unneccesary packages. I am fine with essentials but having to install python when this is achievable via shell scripting is something I wanted to avoid.

Q: Do I have to run this after every reboot?

A: Yes, ASPM changes are runtime-only and reset on reboot.

PCIe register modifications don't persist across reboots. You have several options — the two simplest are:

Option 1: Create a systemd service (recommended)

To apply ASPM automatically at boot, create a systemd unit using the provided sample autoaspm.service.sample.

Example steps to install the unit:

# Copy the autoaspm script to a safe location
sudo cp autoaspm.sh /usr/local/bin/autoaspm.sh
sudo chmod +x /usr/local/bin/autoaspm.sh

# Copy sample systemd unit to directory 
sudo cp autoaspm.service.sample /etc/systemd/system/auto-aspm.service

# Enable and start
sudo systemctl daemon-reload
sudo systemctl enable auto-aspm.service
sudo systemctl start auto-aspm.service

Option 2: Add to startup scripts

# Add to /etc/rc.local (if available)
/path/to/your/autoaspm.sh

# Or add to cron
echo "@reboot root /path/to/your/autoaspm.sh" | sudo tee -a /etc/crontab

Q: How much power savings should I expect?

A: Typically 5-15% system power reduction, varies by hardware.

Factors affecting savings:

• PCIe device types: Graphics cards, WiFi, storage controllers have different impact
• System workload: More apparent during idle or light usage
• Hardware generation: Newer devices generally have better ASPM implementation
• Device usage patterns: Devices that frequently idle see more benefit

License

This project is released under the BSD 3-Clause License ("New BSD"). See the full text in the LICENSE file in this repository.

Credits

• Original bash script: Luis R. Rodriguez
• Python rewrite: z8
• Automatic device detection: notthebee
• Back in Bash: Jacob Olness

Additional Resources

• PCIe ASPM Documentation
• Linux PCIe Power Management
• PowerTOP for easy power savings and analysis
• PCIe Base Specification