Aggressive Link Power Management
|This article needs additional citations for verification. (March 2013) (Learn how and when to remove this template message)|
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.
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. The drawback to this is increased periodic latency as the drive must be re-activated and brought back on-line before it can be used, and this will often appear as a delay to the end-user.
There are three states:
- Low Power with two internal states Partial and Slumber. Partial has a maximum return latency of 10 microseconds while slumber has a maximum latency of 10 milliseconds. Hot swapping is disabled.
- Device Sleep with a maximum return latency of 20 milliseconds unless otherwise specified in Identify Data Log
These can be selected by the SATA AHCI driver, usually via a configuration option. Hot swapping is disabled.
|This computer hardware article is a stub. You can help Wikipedia by expanding it.|