The extra capacity achieved for the 160GB drive comes through a new technology called perpendicular recording, which is being introduced by most of the world's major hard drive vendors and will appear in higher-capacity drives in the next few years.
It works by standing the magnetic fields that represent data bits upright. In today's commercially available drives, the fields lay flat on the disk surface, but standing them upright takes up less space, so more can be packed onto the disk.
Seagate's drive is the first to hit the market, at least according to Seagate. Hitachi is field-testing 100GB drives, but has yet to announce a sale date. In April, Fujitsu announced 200GB drives using perpendicular technology, but not until 2007.
The Momentus 5400.3 drive spins at 5,400rpm and comes with either the Ultra ATA-100 or SATA150 interface.
One will be a 7,200rpm version due next year, although the company did not specify the capacity. Others will come as big as 240GB and be available within a few years.
Seagate is also considering adopting perpendicular recording technology for both its 3.5in and one-inch drives. "There's no boundary. Perpendicular can be used in drives regardless of the form factor," said Tsuyoshi Kobayashi, Seagate regional director.
At the high end, the company will start shipping three new 3.5in 500GB drives in the next six months. The 500GB Barracuda 7200.9, as with prior products in the range, is aimed at high-end PCs. The company is also introducing a new line of products called the DB35 series for video recorders and home servers. Capacities start at 80GB up to 500GB.
At the opposite end of the spectrum, the company is also offering new one-inch drives and, for the first time, will sell its own brand of Compact Flash (CF) card form-factor drives, it said.
The ST1 series for MP3 players and other portable devices comes in 4GB and 8GB versions.