The DVD Forum, the international organization that oversees standardization of DVD and HD DVD optical disc formats, has finally approved version 2.0 of triple-layer HD DVD discs, meaning manufacturers can now begin production of HD DVD read-only discs that can hold up to 51GB (3 x 17) of data. As well, content producers may now start to think about how to use additional capacity. Back in September, the DVD Forum approved version 1.9 specification of 51GB HD DVD media as well as revision 1.0 of triple-layer twin format discs, which can hold up to 30GB of data on its HD DVD side and up to 4.7GB of data on its DVD side. Toshiba confirmed the triple-layer disc structure and its successful operation earlier this year.
More importantly however, neither Toshiba nor the DVD Forum have confirmed that triple-layer HD DVDs will play on existing HD DVD hardware. Fortunately users on dedicated high-definition related forums report that improved 17GB layers actually gained in readability (compared to 15GB layers) and that even first-generation HD DVD players can read three layers. Therefore, it is highly likely that movies distributed on triple-layer HD DVD 51GB discs will be playable even on the very first HD DVD players. It remains to be seen whether triple-layer HD DVDs are more cost-efficient compared to dual-layer Blu-ray discs both in terms of media costs as well as replications costs.
Source:→ Xbit LaboratoriesHD DVD, DVD, Media Storage