The hard disk manufacturer Seagate announced last week (March 23, 2012) that it has achieved the ability to store one terabit of data per square inch of disk. (Sorry about the measurement in inches, but that’s what Seagate, an American company, likes to use in its PR.) In more normal terms, that means relatively soon a standard 3.5 inch hard disk could contain around 6-10 terabytes (trillions of bytes), and the company says the technology could take it to 60 terabytes. Yes, indeed, that is a lot of disk space. How much? Well, back in the day, roughly thirty years ago, Fortune 500 companies could run their IT operations with about a terabyte of storage. An old fart like me can remember spinning new-fangled floppy disks that held a convenient 100K (as in Kilobyte) and 5 MB (megabyte) hard drives cost $15,000 and were as big as a refrigerator. That wasn’t really very long ago, 1980-ish.
Back then I learned, “You can never get enough disk space.” I’m not sure that’s true even now, and with 10 terabyte disks in the next few years, there’s a distinct probability that more people will simply load whatever they want on their disks and forget about storage space. Unless they are professional media artists, our normal but trivial usage will hardly burn through a single disk.
Speaking of burning, the new Seagate technology achieves these mind-boggling storage capacities by using a very sophisticated laser arrangement to heat the metal of the disk just prior to the magnetic imprinting of the data. It’s called heat-assisted magnetic recording (HAMR) and was based on the finding that if the metal is pre-heated, it is much more reliably magnetized and is much less apt to flip bits in the presence of normal operating temperatures. The laser used is very tiny, small enough to heat an area of only 100 nanometers, but the area heated needs to be about 25 nanometers. So the engineers got busy and devised a tiny parabolic mirror to focus the laser beam and further tightened it with a miniscule gold antenna that produces a final heating spot of 30 nanometers. So, in a way, the technology is back to ‘burning disks.’ However it’s done, we definitely seem to be heading toward the day when the question is not ‘How many angels can dance on the head of a pin?’ but ‘How small a device can hold all of human knowledge?’ Seriously.