Though SATA is rapidly replacing IDE bus devices, still the Cd/DVD drives and some hard disks comes with IDE interface. Using 80 conductor cable is much preferable for performance on such devices. The alternate conductors are connected to ground and this avoids crosstalk between lines thus providing a faster data rate. Most people doesnot realise this and even some MNC manufactorers of branded PC like Compaq still ships their PC with 40 Conductor BUS for drives. Check this and change it for better performance!