Short for Advanced Host Controller Interface, AHCI is a specification defined by Intel. It provides software developers and hardware designers a standard method for programming SATA/AHCI adapters and how to program for detection and configuration of the adapters. As of October 2010, the AHCI specification current version was v1.3.
AHCI is supported in Windows Vista and newer Windows versions, as well as Linux operating systems, OS X and other operating systems. In Windows Vista and Windows 7, AHCI is not loaded by default, if AHCI mode was not enabled at the time of installation. SATA controllers typically offer several modes of operation, including legacy Parallel ATA emulation, standard AHCI mode and RAID, which usually has AHCI enabled.