Post by Chris Mellor (thank you) over at El Reg. Finally the HAMR hits
Seagate has demonstrated heat-assisted magnetic recording technology with 1 trillion bits per square inch, a 30 per cent improvement in Toshiba’s production record of 744Gbit/in2with its MQ01ABD drive – a 2.5-inch, 5400rpm, SATA II drive.
Seagate’s highest production areal density is thought to be the 3TB Barracuda, a 3-platter drive with a 620Gbit/in2 areal density. The company says: “The bits within a square inch of disk space, at the new milestone, far outnumber stars in the Milky Way, which astronomers put between 200 billion and 400 billion.”
All current drives use perpendicular magnetic recording technology (PMR), which was introduced in 2006. As HDD manufacturers try to squeeze more data onto the disk platters’ recording surfaces, the bit size in successive generations of this technology shrinks. It is predicted the bits will become increasingly unstable and not hold data properly at the 1Tbit/in2 level and beyond with PMR technology.
In the quest to have smaller bit sizes with stable magnetic charge two main technologies are being investigated. Bit-patterned media (BPM) puts an insulating ring around each bit to stop neighbouring bits influencing its magnetic charge. Heat-assisted magnetic recording (HAMR) uses magnetic material that is more resistant to having its magnetic polarity changed unless it is heated. A heating laser is added to the disk’s read-write head to accomplish the short burst of heating needed to write data to a HAMR bit.
The chart below shows the currently known hard disk drive (HDD) supplier maximum areal densities, together with Seagate’s trillion bit areal density.
Read on here