The right connections

CD and DVD writers typically come with ATA ribbon cables, but you may be better off using the cable that's already installed in your system. Some drives, including the Plextor PX-708A that we used for this article, come with a 40-conductor cable that doesn't support cable select, instead of the slightly more expensive 80-conductor cable that does.

Both 40-conductor and 80-conductor ATA cables use the same 40-pin connectors. The additional 40 wires in the 80-conductor cables, which alternate with the signal-carrying conductors, simply connect to ground. This significantly improves signal quality across the cable, which in turn allows ATA signaling to occur reliably at faster rates than with conventional 40-conductor cables.

How do you spot an 80-conductor ATA cable? One sure way is to count the ridges on the cable. You may also identify a standard 80-conductor ATA cable by its color coding. The master-drive connector at one end of the cable is black, the slave-drive connector between the two ends is gray, and the blue connector attaches to the motherboard. One catch: When the connectors are in use, the visible portion of each is typically black, so you'll have to unplug a connector or two to see if an installed cable is color-coded.

CD and DVD writers don't operate fast enough to require 80-conductor cables, but an 80-conductor cable may improve performance somewhat, and it certainly won't hurt. The 80-conductor cables are mandatory for hard drives using Ultra DMA modes 3 through 6, but optical drives typically use Ultra DMA mode 2 (33.3MB per second), at best. (A higher Ultra DMA mode means that a drive supports a faster transfer rate. The vast majority of hard drives sold today support mode 6.) If you wanted to attach a hard drive and your CD/DVD burner to the same channel, which isn't completely unlikely, you'd need an 80-conductor cable for the hard drive to operate faster than 33.3MB per second.

The bottom line: If you're attaching only optical drives to the cable, don't waste time and money buying an 80-conductor cable. If your PC or new disc burner provides an 80-conductor cable, however, go ahead and use it.