HVDs are holographic versatile discs. They are one next-generation storage technology currently in the research phase. HVDs are specified to store as much as 3.9 terabytes (TB) of data, which is equal to 3,900 gigabytes (GB), or nearly 4 million megabytes of information. The data transfer rate of HVDs is 1 gigabit per second, which is equivalent to 128 megabytes per second, or more than six times faster than high-speed DVD players.
Some people refer to HVDs as next-next-generation, as the technology they are surpassing has yet to become widespread. Both Blu-ray discs and HD DVD offer storage capacities and speeds far greater than DVDs, and both are eclipsed by the specs of HVDs. HD DVDs have storage capacity of 15 GB in a single layer, 30 GB in a dual layer, and 45 GB in a triple layer. Blu-ray discs have a storage capacity of 25 GB in a single layer and 50 GB in a dual layer. Neither come anywhere near to the enormous capacity of HVDs.
HVDs are expected to hit the market during 2006, with initial offerings of discs in the 150-300 GB storage range. These discs will initially cost upwards of US$100 each, with the readers themselves costing over US$10,000. HVD players are designed to be backward compatible with current CD and DVD technology. An organization called the HVD Alliance exists to promote the development of HVDs and associated technology. It is a group of companies, including consumer manufacturers such as Hitachi, Fuji and Mitsubishi.
One reason new disc technologies are needed in the consumer realm is to allow movies to take full advantage of new high-definition televisions. Current DVD technology doesn't allow enough information to be stored to present a true high-definition experience, but solutions such as HVDs provide more than ample capacity and bandwidth to store movies in detail that surpasses the capabilities of existing high-definition televisions. HVD technology works by rethinking the way holographic recording has historically been accomplished. While conventional wisdom has always held that in order to write and read holographic data, two lasers must be used at precise angles, HVDs shine the two beams through a single lens. This allows for a number of significant breakthroughs which have allowed HVDs to surpass previous limits.
The current roadmap set out by the HVD Alliance aims to have 500 GB discs available by the beginning of 2008, with consumer-level recorders by 2009, and full 2 TB discs by 2010. A handful of competing technologies to HVDs exist. The most promising is a technology called Tapestry Media, in development by InPhase Technologies. Tapestry is able to hold up to 1.6 TB and has a bandwidth comparable to that of HVDs. Currently, the Tapestry format does not have nearly as much support as HVDs, so it remains to be seen whether they will present any real competition.