Seagate has managed to double the average hard drive's capability - the firm's U-series drives can pack 40GB of data on to each platter, double the storage space of most hard drive platters today.

Most desktop hard drives today consist of one to four platters or discs, which means Seagate could easily make a 160GB U-series drive.

But that's not going to happen, says Seagate spokesman John Paulsen. Instead, the company's new drives will only store up to 80GB, matching the capacities of major rivals Maxtor and Western Digital.

Why not go higher? There's no need, Paulsen says. Seagate's 80GB drive is already the company's largest. Plus, few people really need a budget drive larger than 80GB, he says.

"We could be shipping a 160GB drive, but the demand for that is small," Paulsen says. Unfortunately for drive vendors, the hunger for additional storage for PCs has tapered off in recent years, he notes.

Seagate began shipping its U-series drives to distributors last week, offering 20GB, 40GB, 60GB, and 80GB versions. Paulsen estimates a street price of around £116 for the 60GB drive and around £170 for the 80GB model.

Seagate's jump to 40GB per platter is more a tweaking of existing production methods than a technological breakthrough, Paulsen says. This incremental approach contrasts with IBM's recent announcement of a new magnetic storage material nicknamed pixie dust that promises to quadruple hard drive capacities by 2003.

Seagate's U series uses traditional technologies to squeeze 32.6GB on to a square inch of platter, a record says Paulsen. And the company may be able to go as high as the 100GB per square inch that IBM is promising, he says.

Seagate and other manufacturers are also working on the same technology employed in IBM's pixie dust, but Seagate doesn't yet see the need to switch to the newer, costlier material, Paulsen says.