8.5GB DVD+R discs, drives to ship April '04

Expect double-layer, almost double-capacity DVD+R drives and media to hit the stores next April, members of the DVD+RW alliance say.

The technology, co-developed by drive maker Philips, and media specialists Verbatim and Mitsubishi Kagaku, adds a second recording layer to a standard-thickness DVD+R disc, taking the medium's capacity from 4.7GB to 8.5GB.

That's enough for four hours of DVD-quality material, 16 hours of VHS-quality content or two hours' archive footage. The discs are playback-compatible with existing DVD players and DVD-ROM drives.

Initial products will offer a write speed of 2.4x.

DVD+R DL, as the technology is known, was demo'd last month in Japan and shown to the press in London last week. Alliance members said the next step is to publish the format's specifications, a process which should be complete this year.

Officially, the Alliance says DVD+R DL hardware and media will ship during "the course of 2004", but privately a number of member companies said they are "hoping" for an April 2004 introduction.

That should provide a further boost for the DVD+R/+RW format, which is increasingly seen as the successor to the older DVD-R/-RW spec., thanks to its full multi-session compatibility with both DVD-ROM and consumer DVD systems. Essentially, DVD+RW discs can be re-edited even when the session has been closed - of 'finalised' - to ensure compatibility with DVD video playback. That said, there have been some claims about the level of DVD+R/+RW compatibility with consumer DVD players; the consensus appears to be that DVD-R/-RW discs, suitably finalised, are more likely to work with any DVD player than is a DVD+R/+RW.

Fortunately, the question of which format to go for is becoming made less relevant thanks to the growing number of DVD burners that support both media formats. The DVD+RW Alliance claims that next year pure-play DVD+R/+RW drives will outsell DVD-R/-RW units four to one. Also, dual-mode drives will also outsell single-format drives. ®