Sunday, April 10, 2005

Hey check me out -- I'm Dancin'! I'm Dancin'!  

Get Perpendicular

Hitachi recently announced perpendicular recording technology, which is meant to improve the density at which bits can be put down on hard disks.

Storage density is exactly that -- the density at which information can be packed onto a storage medium like a hard disk. As density increases, that means that you can fit more data into the same size space, or fit the same amount of data into a smaller space, or both.

Over the years storage density has been increasing steadily. This has led to larger-capacity drives in physically smaller containers. Twenty years ago hard disks were clunkier and held a lot less data. 20MiB hard disks could be purchased but were expensive and rare. Today if you purchase a computer you'll probably get a 50GiB or larger hard disk, or over 2500 times the capacity, and it will take up a much smaller space. That's why the tiny little iPod mini can hold 6GiB of data.

But this rapidly increasing density has led to a problem. Magnetic storage technology is nearing its limits; today we are making bits so small and packing them so closely together that if we go any smaller, bits are in danger of flipping spontaneously from external factors. Since the bits are where your data is stored, you can't have them flipping arbitrarily -- because then you can't read what you just wrote. It'd be like trying to write on an etch-a-sketch that someone is shaking.

The arbitrary point at which this starts to happen and data is lost is called the superparamagnetic limit. Storage technology is getting very close to the superparamagnetic limit. Since bits need to be kept large enough that this doesn't happen, that in turn means that magnetic hard drives are close to their theoretical maximum density.

Hitachi has come up with a dodge that avoids the superparamagnetic limit for a little while longer. Rather than arranging data bits so that their magnetic poles aligned linearly along the surface of the disk pointing at each other (longitudinal recording), Hitachi is arranging them so that their magnetic poles are aligned parallel to each other and pointing away from the surface of the disk (perpendicular recording), with corresponding innovations in how the bits are read and written. This vertical alignment makes them less vulnerable to flipping and again increases the possible storage density. The result is that magnetic bits can be packed several times more densely than before, which means that drives will continue to be able to be made even smaller and higher-capacity than before. For example, rather than 6GiB iPod minis this will eventually make it possible to have 60GiB iPod minis.

It's all very serious and interesting and geeky.

So why exactly did they chose to promote this technology with a crazy Schoolhouse-Rock-style video including "Actuator Man" and little rectangular bits disco dancing?

Good question. Don't get me wrong, I think the video's great... I'm just a little baffled. Then again, it fits right in with Sanyo's HD-BURN promotion. Mr. CD-R, doubling of charming points!

Sometimes this is a bizarre industry I work in. But I'm glad people have a sense of humor about it.