IDE stands for Integrated Device, (or Drive), Electronics. EIDE is a later standard of IDE. It stands for Enhanced Integrated Device, (or Drive), Electronics. EIDE is three to four times faster than the older IDE standard. The picture above shows how to connect an IDE cable to two drives. Using jumpers that are normally located on the back of a drive, the top drive should be made the "master" and the bottom drive should be made the "slave." The master drive is the primary drive. It is normally located at the end of a two connection IDE cable. The slave, or secondary drive, is connected to the IDE cable between the master drive and the motherboard IDE connection. Since data can not go to and from each drive at the same time, it is necessary to make one drive the master and the other drive the slave. IDE cables consist of either 40 individual wires or 80 individual wires. Ultra ATA/66 or later devices need the 80 wire cables to operate efficiently. Most of these wires are used to transfer data between the motherboard and the drives.