DVDs can be manufactured with either one or two data layers. Single-layer discs hold 4.7GB, and are also known as DVD-5s. Double-layer discs hold 8.5GB, and are thus called DVD-9s.

DVD players first entered the scene in 1996 in Japan. The capacity of the original DVD (Digital Video Disc), single-sided, single-layer DVD-1, was 1.46 GB.

Pioneer doubles down on DVD recorder The company follows Sony with a dual-layer machine able to cram 8.5GB on a disc, and boasts of fast single-layer burning.

The DVD+RW camp is expected to be first with products that nearly double the amount of data held on one disc--but that achievement may not win the format war.

By adding one of these drives to your Mac, you’ll be able to create DVDs that can hold as much as 8.5GB of data—almost twice what a single-layer DVD can (see next page).

Hours of Entertainment … The double-layer drives will let consumers store more than 2,000 songs, enough for over four days of continuous music, on a single disc, claims Sony.

A dual-layer drive can store an entire Hollywood DVD-Video title, including menus and special features, on a single dual-layer disc.

The DVD+RW camp is expected to be first with products that nearly double the amount of data held on one disc--but that achievement may not win the format war.

DVD players first entered the scene in 1996 in Japan. The capacity of the original DVD (Digital Video Disc), single-sided, single-layer DVD-1, was 1.46 GB.