Aggressive Link Power Management
Aggressive Link Power Management (ALPM) is a power management protocol for Advanced Host Controller Interface-compliant (AHCI) Serial ATA (SATA) devices, such as hard disk drives and solid-state drives. == Description == When enabled via the AHCI controller, this allows the SATA host bus adapter to enter a low-power state during periods of inactivity, thus saving energy.
Source: Wikipedia — Aggressive Link Power Management (CC BY-SA 4.0)