Get Ready For Blu-ray and HD-DVD

First came the 650-MB CD-ROM. Later came writeable and rewriteable discs that could be burned in a matter of minutes from any desktop. Still later came the 4.7-GB DVD-ROM, followed by writeable and rewriteable variations—again, burnable in minutes from any desktop. But CD technology had one problem: It took several years to migrate from the audio/music world to the desktop.

Now the PC market is on the cusp of another leap in optical disc technology: Blu-ray and HD-DVD. Blu-ray discs store 25 GB per layer, and the standard supports dual-sided discs. HD-DVD, by contrast, stores 15 GB per layer, and it also supports dual-sided discs. But this time, computers and the optical media format are marching hand-in-hand to the starting gate.

If anything, the computer market will represent the majority of the high-density optical market. Howard Locker, director of new technology at Lenovo, predicts the three major suppliers of the players of these new next-generation discs will be PCs, consumer electronics, and gaming machines. "If you look at the volumes, PCs are now more than 50 percent of that total space," Locker recently told Wired News. "So we'll have a big say on who wins."

Both the Blu-ray and HD-DVD formats rely on blue-laser technology. The main advantage: greater storage capacity. While using the same surface area as a conventional CD or DVD, the new blue-laser discs store much more. In fact, a blue-laser disc holds at least 15 GB, and some roadmaps call for as much as 200 GB on a single disc. For the sake of comparison, CD-ROMs max-out at 700 MB, while a double-sided DVD tops out at 9.4 GB.

Also, blue lasers can penetrate through more layers. For instance, while CDs are always single-sided and single-layer and DVDs max out at two layers each on two sides, some Blue-ray discs reportedly offer four layers on a side. More layers per side means that more data can be accessed without having to manually turn over the media or use another disc.

Best of all for user adoption, the physical size and shape of the media for both Blu-ray and HD-DVD formats is essentially unchanged. It's still the familiar round-platter-with-a-hole made famous by music CDs.

Although high-density optical discs and drives are still thin on the ground, this Recipe will give you the tools you need to understand the two new optical formats. Right now, your best tool in the high-density optical market is knowledge.