Toshiba has announced a 60GB 1.8inch hard drive with the claim that the MK6006GAH device has the largest capacity in the world at that size point.

The company has set a new benchmark for areal density in the 1.8-inch HDD category at 93.5 gigabits per square inch. This has allowed Toshiba to pack 30GB of data onto a single 1.8-inch platter, an increase of 50 percent over its previous models. The 60GV device has two platters; its 5mm thick 30GB sibling just one.

The company has a tradition of introducing record-beating small drives. In March this year the Guinness Book of Records certified its 4GB 0.85 inch drive as the smallest HDD in the world.

In comparison, Seagate has achieved a higher areal density: it demonstrated 101 Gbits/sq in using a fully integrated magnetic recording head and multi-layer anti-ferromagnetic coupled (AFC) disc. But its production disks use various densities, some higher still. The Momentus 2.5 inch notebook drives (40, 60 or 100GB capacity) have 83 Gbits/sq in, for example. But the Barracuda 7200.8 personal storage line, with 400GB capacity, uses 108 Gbits/sq in.

The more reliable and the faster spinning a drive has to be, the lower the areal density used. Seagate's Savvio enterprise-class 2.5 inch drive is available with 73GB capacity, less than Momentus' 100GB. It's Cheetah 10K.7 enterprise 3.5 inch drives can store 300GB, less than the non-enterprise Barracuda's 400GB, and a long way short of the 500GB available in its NL35 nearline storage drive.

We will only see 90+ Gbits/sq in areal densities in enterprise-class drives when all the other technology in the drives deliver the reliability enterprises need.

Clearly Seagate could produce a 1.8 inch drive with higher capacity than Toshiba's 60GB. It wouldn't do so until it could provide the spin speed and reliability needed for the application areas: small notebooks; PDAs; and music players.