Get to know the different DVD formats

Understandably, the more companies there are that are involved in the effort to advance technologies, the more difficult it is to get the industry to agree on a single standard.

A case in point is the DVD, which has gained popularity as the media to store movies and a large amount of digital data. The list of companies that play a part in determining the standards include, among others, Apple Computers, Dell, Hitachi-LG, HP, Mitsubishi, NEC, Panasonic, Philips, Pioneer, Ricoh, Samsung, Sanyo, Sharp, Sony and Yamaha. Can you imagine these big names ever being able to work in sync with one another?

One clear solution is for device makers to make their products compatible with as many standards as possible. The eye-catching Ferrari 3000 notebook from Acer that we reviewed last week, for example, is one of the first notebooks that can read and write both DVD+RW and DVD-RW (read: DVD Plus RW and DVD Minus RW).

What standards do we have today? The oldest is the DVD-ROM, which can be played in any of the old players. It includes the DVD that we play on our home entertainment system. The others are DVD-RAM, DVD+RW, DVD-RW, DVD+R and DVD-R. Each has its own merits and demerits, of course.

For now, do not feel intimidated by the standards. They are not as complicated as they seem to be. First, the DVD-RAM is mostly used on computers. It can be written, erased and then rewritten 100,000 times.

The advantage is that it uses a random access method similar to the hard disk. As it gives the fastest data access speed, it is the best choice for data storage. The access speed is so good that we can write a video file and watch another off the same platter at the same time. Needless to say, it cannot be played on a home entertainment system.

The DVD+RW and DVD-RW are both rewritable, just like the DVD- RAM. The DVD+RW, however, is intended to give the best in terms of both performance and compatibility. Unfortunately, because it uses a media with less reflectivity, old DVD-ROM drives and DVD players may not be able to use it.

The DVD-RW is more likely to be compatible with old DVD players and DVD drives. The drawback is that it can be recorded at the slow speed of 1 x (120 kilobit per second). If your current 54 x CD-RW takes around four minutes to burn a CD, you can understand why you may need an hour to record a movie on a DVD-RW. So, the DVD-RW has the best compatibility but very low speed.

DVD-R are the cheapest. They are very similar to the old DVD- ROM, and therefore the right choice for storing movies or game content permanently.

What to choose when buying a DVD drive that can also burn and erase the data on the platter? Currently, it is still a challenging question. Simply choose the one that supports the most standards. The US$300, 4 x I omega Super DVD drive, for example, supports DVD-RAM, DVD+RW, DVD-RW, DVD+R, DVD-R and all CD-RW and CD-R formats (www.iomega.com). You can also opt for the external one, which uses USB 2.0 for the connection to your PC or notebook.

As for the standards themselves, choose DVD-R if you want to make a backup copy of your favorite DVD movie or share data with other people without the need to erase it. For data backup and storage, the choice is clearly DVD-RAM. And, for the rest? Just ignore them. -- Zatni Arbi