4 ms·

>It stops there, and nothing traveling over the SATA cable can be correctly called AHCI. Informally, a lot of BIOSes (another informality there!) would give yo

• wtallis 5y ago
  That choice was largely about which drivers your OS included. The IDE compatibility mode meant you could use an older OS that didn't include an AHCI driver. The toggle didn't actually change anything about the communication between the chipset and the drive, but did change how the OS saw the storage controller built-in to the chipset on the motherboard. The newer host controller interface was required to make use of some newer features on drives, because IDE compatibility mode had no way to expose that functionality. (Later, a third option appeared for proprietary RAID modes that required vendor-specific drivers, and that eventually led to more insanity and user misunderstandings when NVMe came onto the scene.)
• crest 5y ago
  This wasn't about how the SATA controller talks to the drives, but about how the SATA controller is presented to the operating system. The IDE/legacy setting was useful at the time because Window XP lacked AHCI drives on the install media. This compatibility setting simplified the installation of Windows XP on newer hardware which was very common in the DIY space at the time it was introduced. Afterward you could install AHCI drivers and switch to AHCI mode for improved performance (iirc AHCI was required for NCQ).