Check your IDE cables

Upgrade the cabling. As hard-drive technology improves, the cabling requirements to achieve these performance boosts have become more stringent. Be sure to use 80-wire Ultra-133 cables on all of your IDE devices with the connectors properly assigned to the matching Master/Slave/Motherboard sockets. A single device must be at the end of the cable; connecting a single drive to the middle connector on a ribbon cable will cause signaling problems. With Ultra DMA hard drives, these signaling problems will prevent the drive from performing at its maximum potential. Also, because these cables inherently support "cable select," the location of each drive on the cable is important. For these reasons, the cable is designed so drive positioning is explicitly clear.