Two classes of tape storage are jumping to higher densities this week, offering much greater backup capacity and improved transfer speeds.

Hewlett-Packard and Sony on Tuesday announced a forthcoming generation of DAT (Digital Audio Tape) media with twice the capacity of the current technology and a higher transfer speed. On Monday, Sun Microsystems introduced an enterprise-class tape drive that can pack 1TB on a current type of tape, and on Tuesday IBM also announced a 1TB tape drive system.

Along with demand for hard-drive storage that has to be immediately accessible, the need for tape to reliably back up and archive older information is growing fast, according to IDC analyst Robert Amatruda. Higher capacity per tape cartridge can save space, power and money and even allow companies to save more old data, he said. In addition to greater density, the new tape technologies offer faster transfer speeds.

The next generation of DAT, called DAT 320, will be able to hold 320GB of data on one cartridge. It was jointly developed by HP and Sony over the past two years and should be generally available in the first half of next year, according to Bob Conway, manager of the tape product marketing team at HP. The new technology will also allow for back up from disks at speeds as high as 86GB per hour with 2:1 data compression, he said. Data is typically transferred to DAT decks via USB (Universal Serial Bus) or serial or parallel SCSI.

DAT was introduced in 1989 and is still used for audio recording by broadcast professionals, but the market for DAT data storage is quite large, IDC's Amatruda said. Worldwide revenue hit $575 million (£287 million) last year, according to IDC.

HP and Sony co-developed the first four generations of DAT but then pursued separate technologies for several years, Conway said. Continued consolidation in the tape industry helped drive them back together for the development of DAT 320, he said.

To achieve the new density on a tape the same size as its predecessor, DAT 160, the companies changed the basic formula of DAT for the first time, from metal particle tape to metal evaporated tape. They also developed narrower tracks, Conway said. The companies will license the DAT 320 technology to anyone for a nominal fee.

HP and Sony's openness will help ensure there are multiple suppliers of media and components, Amatruda said. HP made 55 percent of low-end tape deck shipments worldwide in the first quarter of this year and Sony made 7 percent, he said.

Although there are a growing number of external hard-drive products available for SMB backups, they aren't as reliable as tape, he said.

"At the end of the day, maintaining hard drives is not really data protection," Amatruda said. And it can be important to have old data set aside for disaster recovery or in case of an event like a tax audit.

"If you can't produce critical data that you use to run your business ... you can be in real trouble," he said. The improved efficiency of the new tapes will probably convince more companies to use them for longer term archiving, he added.

On the high end, Sun and IBM both claimed to have the first 1TB tape technology. Each achieved greater density with new head technologies that work with existing tape cartridges.

The enterprise tape business is also large and growing, with worldwide revenue of $535 million (£267 million) last year, IDC's Amatruda said. It's important for both vendors to support existing cartridge types because large enterprises typically invest in thousands of cartridges at a time, he said. By the same token, it's hard for makers of these kinds of drives to win customers because it can be expensive for large enterprises to switch from one platform to another, he added.

More details of the Sun's 1TB tape drive can be found here.

IBM meanwhile stepped up from its System Storage TS1120 tape drive to the TS1130, which can storage 1TB of uncompressed data per cartridge. Its native data rate is 160MBit/s, so backups can be completed 54 percent faster than with the earlier products, IBM said. The system uses a Giant Magnetoresistive head design to write data more densely on tapes and reduce data read errors, the company said. It uses current 3592 rewritable and WORM (Write Once, Read Many) cartridges. The TS1130 will ship on 5 September with a starting price of $39,050 (£19,530), and customers will be able to upgrade their current drives for $19,500.