I successfully installed AHCI driver on my 2006 Mac Pro running 64 bit Windows 7. I re-ran the Windows Performance Eval after the AHCI update. Interestingly, my disk score did not change: 5.9 prior to the update and the same after the update. My boot Win 7 drive is a 300gig Velociraptor drive (the drive is dedicated to Win 7). Can someone tell me why the disk score did not improve. I thought that changing from IDE to AHCI would lead to a substantial improvement. Thanks for a response.