Do Blu-ray discs have more storage capacity, and is it relevant?
The present myth is that Blu-ray discs hold 50 GB of data, and HD-DVDs hold 30 GB. Blu-ray stores more information in a single layer than does HD-DVD, the difference being 25 GB for Blu-ray vs. 15 GB on HD-DVD. However, at the moment, Blu-ray can only produce single-layer discs. So the total storage capacity on all Blu-ray discs that have been brought to market thus far is 25 GB. Meanwhile, from the outset HD-DVD has been delivering dual-layer discs that hold a total of 30 GB on a single side of the disc. In addition, HD-DVD can presently encode dual-layer information on both sides of the disc, for a total of 60 GB per disc. Dual-sided encoding has been used so far in HD-DVD “combo” discs to put the HD version of a movie on one side, and the standard def version on the other. But both sides of the disc can be encoded in HD if the space is needed. So as of now, HD-DVD is capable of delivering 60 GB of storage on a two-sided disc compared to Blu-ray’s 25 GB single-side, single-layer limi
