Tablets mean tubby HDDs must get thinner - A*STAR

Tablet computers need skinnier hard drives to provide more capacity than flash, with flash caches adding speed to the single spinning platter mix.

Researchers at the Singapore-based A*STAR or Data Storage Institute, which has been popping up in El Reg's pages quite a lot recently, think that current 7mm-thick single platter 2.5-inch drives, such as Seagate's Momentus Thin, are too thick for tablets. They believe it would be smarter to have thinner drives, specifically 5mm thick.

The DSI researchers think 200 million tablets could be sold in 2014 so the opportunity to improve storage performance is a good one. A statement from the institute read: "Thin hybrid drives would provide a good alternative to Flash memory due to the scaling and performance limitations of Flash memory... Hybrid drives could potentially lessen power consumption, reduce costs and increase storage capacity." The researchers estimate that hybrid drives could lower power consumption by around 30 per cent compared to hard disk drives, but they don't say on what basis the comparison is made.

The DSI researchers are proposing to develop a hybrid disk drive that could fit inside an iPad, 0.34-inches (8.8mm) thick, and describe how they could do it with a thinner motor thus:

One of the main challenges faced in scaling down the thickness of a hard disk drive is the ability to scale the thickness of the current spindle motor while maintaining the motor performance such as the non-repeatable run-out (NRRO). DSI has designed an axial field motor (the current motor is based on a radial field design) that is 4mm thick, and can spin at 5400/7200 revolutions per minute (rpm). The axial field design eliminates cogging torque and unbalanced magnetic pull that in turn helps to reduce friction loss of the bearing, vibration and acoustic noise. This novel and slim spindle motor will be demonstrated in DSI's thin drive with a 5 mm thickness.

Dr Pantelis Alexopoulos, DSI's executive director, waxed lyrical about this, saying: "DSI is very excited about the direction that we are taking. We strongly believe there is an opening in the market for thin drives. We are capitalising on our years of R&D experience in hard disk drive and data centre technologies and are working passionately to make the concept of thin hard disk drive into reality."

It may be telling that none of the hard disk drive companies have pushed motor manufacturers to produce thinner motors, as far as we know. Perhaps they think the tablet hard disk drive opportunity is a figment of DSI's imagination or they may actually have their own, skinnifying drive effort. They wouldn't do this though, without qualifying the opportunity with tablet manufacturers, and there are only two that count, currently: Apple and Samsung. Maybe ultrabooks might be a more realistic target for hybrid flash/single platter drives. ®