If you can’t see your AHCI Link Power Management from the Power Options, there is a way to add it. Always backup your computer before modifying the registry.
You can add the GUID to the registry by going opening the registry (regedit) and creating a key under the following key -0012ee47-9041-4b5d-9b77-535fba8b1442
The easiest way is to copy the information in italics to notepad or notepad++ and save as AHCI.reg.
After saving this, double click on the .reg file and reboot.
Windows Registry Editor Version 5.00
So what are the settings used for? Using DIPM can add 7% to 8% more battery time according to some articles.
|0||Active||Link power management is not used.|
|1||HIPM||Host-Initiated Power Management (HIPM) is used.|
|2||HIPM and DIPM||HIPM and Device-Initiated Power Management (DIPM) are used.|