Setup as AHCI the hard drive controller is under IDE ATA/ATAPI controllers and is shown as a IDE device in System Information. If I set it up as IRRT the hard drive controller is under Storage Devices and System Information shws it as a SCSI device. The both are using IRQ 19, but I was curious if there was a perfomance difference in the two different setups. I'm asking this from a pure technical standpoint as I'm there is some software that I could use to test it and I probably will if I can find this type of software. Thanks!!