History 2005: Finally First PMR HDD

Winchester drive histories will recall that on December 13, 2004, Toshiba was the first firm to announce a hard disk drive using magnetic perpendicular  recording (PMR) when all other HDDs were based on longitudinal recording  since the technology’s invention in 1956.

On paper, the difference is simple: instead of having horizontal magnetic fields on the  surface of a disk, they are instead  vertical, which should allow for better areal density, here an industry leading 133Gb/square inch.

In  practice, however, the matter is far from simple, since new magnetic heads and platters assembled with great delicacy are required. 

According to an internal source at Toshiba questioned by our U.S. technology correspondent Jacques Kauffman, the heads of the new mini-devices from the Japanese  company apparently come from TDK, while the platters are from Showa Denko or Hoya. 

In reality, what does this new technology bring today? Not much, apparently, in terms of technical specs, which seem pretty classic here. Even the 80GB capacity, a world record in a 1.8-inch  HDD, was matched by Hitachi GST’s announcement of its Slim 3 weeks later.   

What is important in this domain, however, is that perpendicular recording, with its smaller grain  size, will most likely allow rotating devices once again to grow more rapidly in capacity, staving off yet  again the superparamagnetic limit soon to be reached in longitudinal recording.

Which is why not only Toshiba, but all HDD makers are working at lightning speed in this  area.

Let’s salute Toshiba, then, for  being the first, if clearly not the last.

The Japanese maker has produced more than 10 million 1.8-inch devices since the launch of its first 2GB unit in 2000, but it also plans to use this new recording mode on its forthcoming 0.85-inch HDD (see  below) to come in order to push capacity of its 2-4GB model to 6-8GB. 

Recall that the first devices with perpendicular recording date from 1988. At the time, they were 5.25-inch and 3.25-inch floppy disk  drives from Maxell and Toshiba (even then) respectively. The 3.5- inch unit, with its 2.88MB, supported by IBM for its PS/2 computers, were expected to succeed the 1.44MB diskettes, but proved to be a floppy flop.

In the early 90s, a start-up known as Censtor also ventured into perpendicular magnetic HDDs, there again  without success.    

This article is an abstract of news published on issue 205 on January 2005 from the former paper version of Computer Data  Storage Newsletter.