ryzen-auto-undervolt

A simple systemd package that uses ryzenadj to apply different --set-coall values based on power source:

• AC power: apply AC_UNDERVOLT
• Battery power: apply BATTERY_UNDERVOLT

Configuration is stored in /etc/default/ryzen-auto-undervolt.

Value Rules

• Allowed range: -30 to 30
• Negative values mean undervolt
• Values are converted to the 20-bit format required by ryzenadj --set-coall=0x...
• Example: -16 becomes 0xFFFF0

Requirements

1. ryzenadj is installed
2. Your device supports --set-coall
3. ryzenadj -i works correctly

Example:

sudo /usr/bin/ryzenadj -i

Or if you use a custom path:

sudo /home/deck/.local/bin/ryzenadj -i

Configuration

After installation, edit:

sudoedit /etc/default/ryzen-auto-undervolt

Default values:

RYZENADJ_BIN=/usr/bin/ryzenadj
AC_UNDERVOLT=-30
BATTERY_UNDERVOLT=-10
DRY_RUN=0

systemd Behavior

• ryzen-auto-undervolt.service runs once at boot
• A udev rule monitors Mains state changes in power_supply
• Plugging/unplugging power triggers the same service again

View logs:

journalctl -u ryzen-auto-undervolt.service -b

Build a deb Package

Run in project root:

dpkg-buildpackage -us -uc -b

Install the built package:

sudo dpkg -i ../ryzen-auto-undervolt_0.1.0-1_all.deb

If debhelper is not available, use the included script:

./build-deb.sh
sudo dpkg -i ./ryzen-auto-undervolt_0.1.0-1_all.deb

Manual Test

sudo systemctl restart ryzen-auto-undervolt.service
sudo systemctl status ryzen-auto-undervolt.service --no-pager

Stability Notice

--set-coall tuning can affect stability. Increase/decrease gradually (for example -5, then -10) instead of using aggressive values immediately.