Advantages of Using DVDs as Data Storage Devices

There are many types of digital storage media now available in the market to cover all price ranges and data capacities. These range from floppy drives and optical disks to tape drives, USB drives and portable hard disks.

Floppies are now more or less obsolete. Tape drives are not used for much more than keeping archival data backups. Portable hard drives as well as USB drives come out to be quite expensive. There is only one portable storage device that is a perfect match of low price and high capacity. It is the optical disk.

Optical disks are small circular disks made up of plastic that is very difficult to break or crack. It is quite thin and light, with an overall size that can easily fit in your hand. The optical disks are of two types – compact disks (CDs) and digital versatile disks (DVDs). The former is old technology, first launched in the early eighties.

It holds about 4.7 GB of data and is today one of the cheapest portable storage media available in the market. In the last five years or so, another version of optical disks with a much higher-capacity – the DVDs – has become extremely popular. It has a whopping 4.7 GB capacity, that in some types of DVDs can go up to even 17 GB.

All DVDs work with an optical drive. These have become quite cheap and affordable now because of mass production. The drive has a tray which slides out on the press of a button to receive the DVD. The heart of the optical drive is made up by a read / write head that can emit and read a laser. There is also a powerful motor that can spin the disk at a very high speed.

The DVD records data only on its one side. This shiny data-recording surface can be modified by a laser. How data gets recorded on the disk is interesting. The laser from the drive can etch a pattern of microscopic pits in a long, unbroken groove that starts at the centre hole of the disk and goes around again and again tightly, gradually moving toward its edge. Each pit represents one and its absence represents zero, thus making recording of digital data possible.

To read the data, the laser emitted by the head bounces off the disk surface. It is read by the drive lens and the operating system makes sense of it, turning it into meaningful data.

Pros

A DVD has many benefits as a data-storage device. It is quite rugged and virtually indestructible. It cannot be broken or cracked easily and can last for up to ten years or even more without any problem. Billions of DVDs are produced every year in the world. This has ensured economy of scale. The DVD as a result is one of the cheapest storage media available in the world.

The storage capacity of a DVD is extremely high. It can comfortably store a full-length Hollywood blockbuster or hundreds of songs. The disk is quite thin and dozens can be easily stacked up over a single spindle, without taking up too much space on a table.

Cons

The biggest drawback of a DVD is its exposed data-recording surface. This creates many problems since there is no protection against surface contaminants and anything which obscures or smudges the pattern of pits on the disk surface will interfere with the reading of the data.

Dust may settle down on the disk surface, it may be scratched or some thick liquid may spill over it, thus making it difficult for the laser to make sense of the pattern of pits. DVDs are made of plastic which are sensitive to strong heat. Thus, they have to be kept away from fire as well as direct sunlight.

Future

The optical disks were launched a decade ago and well and truly revolutionised the portable data storage market that was till then monopolised by floppy disks. The latter had a puny storage capacity and were quite unreliable. Much water has flown down the bridge since then. Today, the floppies are history and optical disks rule unchallenged in the world of storage devices, but the competition is already here in the form of USB drives.

These use no separate drive mechanism and are quite self-sufficient. Just plug them into the USB port and you are ready to go. Currently, the drives are a bit expensive compared to the DVDs, but as the technology matures, the cost may come down and they may become as competitive and cheap as optical disks.

James Walsh is a freelance writer and copy editor. If you are concerned about data loss and would like more information on Data Recovery see http://www.fields-data-recovery.co.uk