Why Can't My DVDs Hold as Much as Other DVDs?
Sharful wants to copy some DVDs, but they contain more information than will fit on his blank discs.
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. (Why do I suspect someone in PR came up with those names?)
The vast majority of stamped DVDs--those you buy with movies and TV shows already on them--are DVD-9s. You can usually, but not always, recognize them by their gold-colored data side (the side without the label). But most blank discs are single-layer DVD-5s.
You can burn double-layer discs, but it will cost you. You might even have to upgrade your hardware, as not all DVD drives can write to dual-layer media. Check your drive's documentation to see if it supports Dual Layer or DL media.
The discs also cost more. Checking Best Buy's web site as I write this, I find a 25-pack of DVD+R's selling for $10, and a 5-pack of DVD+R DL discs for $20.
By the way, stamped DVD's can also be double-sided as well as double-layered. That means the studios can release movies on DVD-10s (a single layer on each side), DVD-14s (a single layer on one side; a double on the other), and DVD-18s (two layers per side). They rarely do, however, probably because people will pay more for a two-disc set than for a single disc--especially an ugly single disc with no place for a label.
Visit http://forums.pcworld.com/message/149119 for the original forum discussion.