Changes
== AHCI Link Power Management ==
AHCI Link Power Management is a technique mechanism where the SATA AHCI controller puts the SATA link to the internal HDD and/or SSD disk into a very low power mode when there's no IO (input/output) activity for a while. The controller automatically puts the link back into active power state when there's real work to be done. This is done to save power consumption by the HDD and/or SSD disk.Tests show that this can save around 0.4 Watts of power and decrease mSATA average temperature.
* HIPM = Host Initiated Link Power Management
* DIPM = Device Initiated Link Power Management
=== Linux ===
* Create text file /etc/pm/power.d/sata_alpm
#!/bin/sh
for i in /sys/class/scsi_host/host*/link_power_management_policy; do
echo min_power > $i
done
* Make it executable
$ sudo chmod +x /etc/pm/power.d/sata_alpm
* Reboot, check that SATA power management policy have been changed
$ cat /sys/class/scsi_host/host*/link_power_management_policy
min_power
min_power
