Hoping to address increasing user demands for storage capacity, Hitachi Global Storage Technologies last week unveiled a pair of 2.5-in. hard disk drives for notebook computers and mobile devices.

The Travelstar 5K500 disk drive will be available in February in 400GB and 500GB versions, priced at about US$350 and $450, respectively.

Both versions incorporate three-spinning-disk configurations and perpendicular magnetic recording technology, the company said.

A third version of the Travel star 5K500 includes a bulk data-encryption security option with a 1.5Gbit/sec. Serial ATA interface, according to the company.

IDC analyst Richard Shim said the new half-terabyte 2.5-in. drives may help suppliers keep up with growing demand for storage capacity -- at least in the short term.

"We are starting to approach that threshold where we're pushing the outer limits of how much capacity we really need," he said. "If you ask anybody, they never say they have enough storage."

Shim said Hitachi's three-disk, 2.5-in. drive configuration shouldn't create greater heat output or performance problems than traditional 2.5-in. two-disk models.

However, he cautioned that over the long run, continued efforts to significantly increase drive capacity and the number of spinning disks on a device will likely cause data management and hardware maintenance problems for users.

According to Hitachi, the Travelstar 5K500 drives can hold up to 125 hours of high-definition video, 500 hours of standard digital video, 178 feature-length non-HD movies or 125,000 four-minute songs.

The 12.5mm storage device can operate at speeds of up to 5,400 rpm and includes rotational vibration safeguards and a 3Gbit/sec. SATA interface.