Toshiba pushes hard disk density higher

Engineers at Toshiba have demonstrated a working prototype of a hard disk drive that crams in 50% more data than previous models...

Engineers at Toshiba have demonstrated a working prototype of a hard disk drive that crams in 50% more data than previous models and opens the way to higher capacity hard disk drives (HDDs).

The drive manages to pack 52Gbits of data into one square inch of magnetic recording space. This represents a big jump from the company's current highest capacity commercial drive, a 2.5-inch, 20Gbyte model that has an areal density of 35.1Gbits per square inch (bpsi). In contrast, the areal density achieved with the prototype drive translates into a capacity of 30Gbytes per 2.5 inch platter.

The company says it expects the technology won't find its way into commercial products until later this year or sometime next year. Meanwhile researchers are already concentrating on doubling drive capacity to 100G bpsi before the end of 2003.

Toshiba is in a race with other leading hard disk drive makers to increase areal density and so come out with higher capacity hard disk drives. This is especially important for drives with platters - the circular discs coated with a magnetic material on which data is recorded - of 2.5 inches in diameter and below because their smaller size means there is less physical space for data.

IBM's latest 2.5-inch drive, the Travelstar 40GN, has an areal density of 34G bpsi and capacity of 20Gbytes per platter while Fujitsu MHR series 2.5-inch drives, which were introduced in October, boasted a 36.1G bpsi areal density but still 20Gbytes per platter.

Toshiba is also hoping to produce even smaller drives. In May 2000 the company put on sale its first 1.8-inch hard disk drive. Initially available with a capacity of 2Gbytes, a 5Gbyte version of the drive went on sale last year and in January this year Toshiba announced 10Gbyte and 20Gbyte versions. The drives weigh just 62 grams and are small enough to be packaged inside a standard type-II PC Card case, making them perfect for use as a bridge media for transferring files between devices or as expansion storage space.

In addition to hard drives for computer use, the company also revealed some of its development work underway aimed at drives for new applications.

Development of a new type of Audio-Visual hard disk drive (AV-HDD), for use in consumer electronics products, is almost complete and the drive is expected to be on the market before the end of March. Unlike drives for computer use, AV-HDDs impose time limits on the speed with which information can be read off the drive so as to ensure a steady video or audio stream. One of the side-effects of this is increased noise, said Yutaka Arakawa, a specialist in Toshiba's hard disk drive development department.

The new drive, a 40Gbyte 2.5 inch model, cuts most of the noise usually associated with AV-HDDs but retains the time limit on read operations to ensure a smooth stream of data, he said.

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