What is a Double Layer DVD Drive? Dual Layer DVD Disks Explained
Optical drives have become a standard accompaniment to new computers since compact discs (CDs) hit the scene in the late 1980s and early 1990s. Not long after this time, computer users outgrew the 650-megabyte storage limit of CDs and looked for storage options that avoided the dangers of losing data on magnetic media and afforded users the convenience of optical storage.
DVD burners entered the market in the late 1990s but there was one major problem. The price of these burners prohibited many people from buying them. For those early adopters who did opt to spend big money for DVD burners, they soon found out that the storage capacity to cost ratio did not warrant the expense. Early DVD media only held about 4.7 gigabytes of data, which is only about the capacity of 7 or 8 CDs.
The price of DVD burners dropped dramatically and it wasn’t long before double or dual layer DVD burners and media hit the market. Double layer DVD media are capable of holding about 8.5 gigabytes of information and are far more economical than the early days of DVD burners.
What is a Dual (Double) Layer DVD?
Single layer DVD burners are made from a single “dummy” layer of polycarbonate. They contain one layer of organic dye that make recording of digital information possible. A laser in a single layer DVD burner only needs to focus on this one layer to read and write data. Again, single-layer DVD burners and media can record and hold up to 4.7 gigabytes of data, which is about 1,500 to 1,600 MP3 files.
Dual layer DVD burners contain two layers of organic dye. The laser within the DVD burner is capable of focusing on one layer at a time so that data from one layer is not confused with data on the other layer.
Dual-layer DVDs (also known as DVD9) are the same DVDs pressed by Hollywood to distribute its collection of movies on DVD format. Because DVD9 can hold much more than a single-layer DVD, movie studios can use much less compression for both video and sound when transferring a movie from film to digital format. The result is better picture quality, better sound quality, and enough space for extras such as subtitles, language dubbing, and trailer video information.
Cost Effectiveness of Double (Dual) Layer DVDs
You can purchase DVD9 burners for well under $50, which are more than adequate for the average home user. These burners normally ship complete with burning software such as the popular Nero Express media creation program. This software offers a complete suite of applications such as the ability to burn CDs, DVDs, DVD9s, create ISO images, and much more.
Dual Layer DVD media cost around $1 per double-layer DVD. Buying dual-layer DVDs in bulk saves money, so if you are going to be doing a lot of burning, save yourself some money and buy the largest pack of discs you can afford at one time.
Dual Layer DVD Formats
Most modern dual-layer DVD burners are capable of burning in all of the available formats such as DVD+R and DVD-R. As long as your DVD burner can burn all of these formats, there is little to worry about which disc format to buy. The result of burning a DVD+R and DVD-R is the same to the end user. The only difference lies in how the DVD burner actually writes information to the disc. Unless you are a high-tech person who just needs to know, don’t worry about which format you use to burn your DVDs.
As with CDs and single-layer DVDs, dual layer DVDs are available in write-once discs (DVD9-R) and rewritable discs (DVD9-RW). You can write to DVD9-R discs only once although you can create multi-session discs. DVD9-RWs are rewritable, allowing you to record information to these discs multiple times. Which to choose depends on the application. For videos and music to be used in a DVD player, choose the R type of discs. For backups and transport media, choose RW-type discs. Using RW-type discs can be quite economical since they can be written to multiple times. Much like a hard drive, you can write, rewrite, and write over information repeatedly on these discs.
Conclusion
Dual layer DVD burners and media allow you to write much more information to a disc than older-generation single-layer DVDs and CDs. The cost of double-layer DVD burners has dropped significantly in recent years making them standard complements in new computers. DVD9 discs have also dropped in price to about $1 per disc, depending on how many you buy at one time. To save money, buy as many discs as you will need, in bulk, thus lowering the cost per disc.
