Hmm...If I remember correctly with AHCI drives can be 'hot swappable' and run faster. The SATA3 or SATA6gb/s mode isn't achievable under IDE. This guide I found helps a little and explains it much better than I: http://www.diffen.com/difference/AHCI_vs_IDE Your SSD will or should run faster now. I'd also check your motherboard manual (you can download a copy from the support page) as to which SATA ports are which speeds. Your SSD ideally should be in the fastest slot. If you post the make and model I'll look for you.