Change IDE to AHCI mode

Circa 2008

Subtle, but often forgotten performance gain.

🚧 This was written around the time INTEL publicly released its first wave of SSD's. I was fortunate enough to pick up a 40gb model for the OS🚧

AHCI stand for Advance Host Controller Interface. AHCI is a hardware mechanism that allows software to communicate with Serial ATA (SATA) devices (such as host bus adapters) that are designed to offer features not offered by Parallel ATA (PATA) controllers, such as:


Native Command Queuing (NCQ) -might improve computer/system/hard disk responsiveness, especially in multi-tasking environmentThe detailed steps from Microsoft website are as follows:

  1. Press Start then RUN

  2. Now type regedit there and press Enter Key to open up the Registry Editor Window.

  3. If you receive the User Account Control dialog box, click Continue.

  4. Locate and then click the following registry subkey:

      1. HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\msahci

  5. In the right pane, right-click Start in the Name column, and then click Modify.

  6. In the Value data box, type 0 [3 is default], and then click OK

  7. Reboot and enable the AHCI setting in your BIOS.

  8. Alot of times during a fresh intall windows will automatically do steps 6 & 7 for you.