Power management
lastmod 2026-03-31created 2020-06-277 edits
Power management is a feature of some electrical appliances, especially copiers, computers, CPUs, GPUs and computer peripherals such as monitors and printers, that turns off the power or switches the system to a low-power state when inactive. In computing this is known as PC power management and is built around a standard called ACPI. This supersedes APM. All recent (consumer) computers have ACPI support.
In the military, power management often refers to suites of equipment which permit soldiers and squads to share diverse energy sources, powering often incompatible equipment.
Utilities
- upower
- systemd (adjusting laptop screen-off behavior, etc.)
- Advanced Power Management (apm)
- Advanced Configuration and Power Interface (ACPI)
Keeping a laptop running with the lid (LID) closed
See Systemd#Adjusting laptop screen-off behavior.
AC Power Recovery (automatic boot when power is restored)
This feature is configured in the BIOS/UEFI and makes the computer turn on automatically when power is restored after an outage or when it is plugged into an outlet.
How to configure it in BIOS/UEFI
Press the DEL or F2 key during boot to enter the BIOS, then look for the setting at one of the paths below, depending on the manufacturer.
Common paths:
- Advanced → Power Management → AC Power Recovery (or After Power Loss)
- Power → APM Configuration → Restore on AC Power Loss
Values:
- Power Off (default) — stays off even when power comes back
- Power On — boots automatically when power comes back
- Last State — restores the state (on/off) just before the outage
Change it to Power On and save.
Names by major manufacturer
| Manufacturer | Menu location / item name |
| ASUS | Advanced → APM → Restore AC Power Loss |
| MSI | Settings → Advanced → Power Management → Restore after AC Power Loss |
| Gigabyte | Power → AC BACK |
| ASRock | Advanced → ACPI Configuration → Restore on AC/Power Loss |
| Dell | Power Management → AC Recovery |
| HP | Advanced → Power-On Options → After Power Loss |
| Lenovo | Power → After Power Loss |
| Intel NUC | Power → Secondary Power Settings → After Power Failure |
Notes
- Almost all server/industrial PCs support this option.
- Some low-end motherboards may not have this option.
- Enabling this setting on equipment that must run unattended (e.g. k3s cluster nodes, Edge PCs), together with a UPS, allows automatic booting after power is restored from an outage.
- It is a separate feature from Wake-on-LAN (WOL); WOL boots remotely via a network packet.