THEORY AND PRACTICE

What's Next For Magneto Optical Users?

by Lowell Rapaport

Magneto optical (MO) and write once, read many (WORM) storage are well known for their durability, performance and archival qualities, and they're still a popular choice with document management users. But with the emerging popularity of DVD, what is the future of MO?

This question becomes all the more relevant since Maxoptix, one of only two companies that manufactured MO drives, has exited the MO drive and jukebox business in order to concentrate on tape libraries (although it will still support existing MO products in the field).

From a technical standpoint, MO discs are often preferred to tape because the media are less susceptible to physical wear under heavy use; they're also faster for active archives. MO and WORM discs are also recommended for use in long-term archival storage. MO discs have a theoretical shelf life of 50 to 100 years and are often the format of choice for critical data. Competing optical technologies such as DVD-RAM, DVD-RW, DVD-R and CD-R have shorter expected life spans — five to seven years for CD-R and DVD-R and 10 to 30 years for DVD-RAM.

The main drawback of MO (other than its higher cost than CD or DVD) is the fact that the technology has reached its limit of development. The last format to be backward compatible with the installed base of MO discs will be 9.1-gigabyte MO drives (also known as 14x). Sony, now the only manufacturer of MO drives, promises to support the format going forward.

"We will continue to support the current generation of MO technology," Sony declared in a recent statement. "The next generation of magneto optical technology, Ultra Density Optical (UDO), is on track for release in 12 to 18 months."

UDO discs are expected to hold 30GB to 40GB. UDO discs will not be compatible with current MO technology, and Sony hasn't indicated whether the drives will be able to read or write legacy MO or WORM discs.

UDO drives will be manufactured by Plasmon as well as Sony. "UDO discs will use an inorganic phase change technology, similar to what is used by CD-RW and DVD-RAM," says Damon Ujuarosy, vice president of engineering at Plasmon. "The write-once version of UDO will have a 100-year life expectancy." Ujuarosy says the company is working on improving the life span of the rewritable UDO discs to match that of MO [discs].

The bottom line is that if you have legacy MO or WORM discs, they'll easily outlast your need for the data they contain. If you don't have an installed base of MO and WORM discs, tread cautiously. If you need the highest capacity, most rugged and long-lived format available, you may want to leave yourself an upgrade path to UDO when that format becomes available in late 2002 or early 2003.