A*Star Aims to Produce HDD With Only 5mm Thickness for Tablets

Any future?
This is a Press Release edited by on 2011.11.18

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Tablets are fast becoming the media device of choice nowadays for work and play, particularly with the advent of iPads and the Samsung Galaxy Tab into the mobile device market. With a volume of 19.5 million of media tablet sold in 2010, and the sales volume is projected to reach over 200 million units by 2014. As media tablets seem to be an emerging trend and continues its expansion into mass consumer market, there is a lot of potential to improve the performance of the media tablet, especially in the area of memory and storage.
Although the current memory and storage of choice for tablets is flash memory, the A*STAR, Data Storage Institute (DSI) believes that moving forward, thin hybrid drives would provide a good alternative to Flash memory due to the scaling and performance limitations of Flash memory. Additionally, hybrid drives could potentially lessen power consumption, reduce costs and increase storage capacity. Currently, the thinnest hard disk drive in the market for a 2.5 inch form factor is about 7 mm. However, in order to break into the media tablet market, the ideal thickness of a hard disk drive should be 5 mm or less.

           Overall thickness of the first prototype
      of DSI's thin hybrid hard disk drive is 5mm.

Researchers at DSI aim to produce a hard disk drive thin enough to fit into a tablet, taking the thickness of the current iPad2 (which is at 0.34 inch or 8.8 mm) as the benchmark target. The DSI also proposed a hybrid architecture in order to mitigate the issues of portability, reliability of data, and power consumption. Compared to Flash or SSD, hybrid drives can provide a larger storage capacity, and performances at a lower cost; whilst compared to hard disk drives, hybrid drives can reduce power consumption by about 30%.
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 5400/7200rpm. 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 5mm thickness.
"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," said Dr. Pantelis Alexopoulos, Executive Director of DSI.

Our Comments

A*Star has excellent engineers in Singapore and it's remarkable to have designed such a motor only 4mm thick and able to spin at 5,400rpm and 7,200rpm, as well as a prototype of a 5mm z-height HDD.

But we don't see today which HDD manufacturer will decide to produce it. Toshiba is the last firm in drives with a form factor under 2.5-inch, mainly for Apple for the iPod classic integrating 160GB 1.8-inch rotating memory.

The thinnest HDD is also currently from Toshiba with a 1.8-inch drive at 220GB and 5mm z-height (54x71x5mm) at 4,200rpm and using a low-insertion force SATA connector. Here maybe Toshiba could be interested to increase the rotation speed to 5,400rpm and 7,200rpm with the new motor. Nevertheless, A*Star or Toshiba will have to find a manufacturer to produce this special motor in sufficient quantity.

A*Star expects to see its 5mm z-height drive to be used for tablets. Today the only known tablet with HDD is the Archos 70 Android unit packing a 250GB 2.5-inch HDD, the Momentus from Seagate, with 16GB of flash memory. On its side, the Toshiba Thrive tablet uses flash only. That's the same for the iPad, even if flash is the most expansive component of the unit after the screen.

For sure the price of flash limits the capacity for tablet's users. It's only up to 64GB for Apple iPad. But, as everybody knows, HDDs - even hybrid models with some flash memory as a cache - use more power, are slower and have lower operating shock than flash memories. Their only advantage is price: 64GB of flash memory runs at $120 while a 160GB 1.8-inch Toshiba disk drive can be found at less than $60.

A lot of companies tried to enter into HDDs in small form factors and died or finally stop them:
  • In 0.85-inch form factor: Samsung and Toshiba
  • In one-inch form factor: Cornice, Halo Data Devices, Hitachi GST, IBM, GS Magicstor, Ritek, Seagate, Thin Spin and WD
  • In 1.3-inch form factor: HP, PicoDisk, Samsung
  • In 1.5-form factor: Ecol.2
  • In 1.8-form factor: Areal Technology, Aura Associates, Calluna, Conner Peripherals, Hitachi (MiniStor), Hitachi GST, IBM, Intégral Peripherals, Maxtor, MiniStor, NEC, PicoDisk, Samsung, Seagate, SyQuest and WD