*** The good news with Windows10 is you do not need to change anything in the OS. Just change the BIOS and reboot.
Here is the difference with my 75GB Raptor. Seems too large a difference but seeing is believing. Windows experience index did not change but the Raptor has less chatter and things are perceptively smoother.
AHCI (Advanced Host Controller Interface) enables native command queuing and hot-plugging through SATA host controllers (Serial-ATA) for your hard drives. In many scenarios it enables more efficient multi-tasking. Vista was the first Windows OS to support AHCI out of the box, where as Windows 7 does the same. But an issue with AHCI is that if you install the OS without enabling AHCI in the BIOS, enabling it after installation will render your OS unusable. This is because Windows disable the AHCI driver since it is not needed during the installation.If you installed Windows and used IDE, the change is easy. Go to above link for directions. Improvements may be marginal but SSD's usually want AHCI, so if you are changing to SSD this quick change will help. Look for the reg hack for quick and easy.
Here is the difference with my 75GB Raptor. Seems too large a difference but seeing is believing. Windows experience index did not change but the Raptor has less chatter and things are perceptively smoother.
Before
After
