Perpendicular Hard Drive Recording

Factual Questions
1

I read an article on the internet that says companies are researching a new way to store data on hard disk drives. They do this by storing the bits perpendicularly instead of longitudinally. This has me completely confused. How is data stored on a HDD currently?

What I understand this article to mean is that the researchers have found a way to store a bit as ‘|’ instead of as ‘-’. But if this interpretation is correct, then I can’t see how the drive can store more data as the volume of the bits remains the same, their orientation has just changed. Can anyone help me understand this better?

Article to which I am referring: http://eetimes.com/sys/news/OEG20030718S0038

2

I get the impression that the idea is to record the magnetic orientation like this:

N
S

Rather than like this:

NS

Allowing the bits to occupy less space.

3

To clarify, notice what happens when we store say, eight bits that way:

NSNNSNSS
SNSSNSNN

As opoosed to the current way:

NSSNSNSNNSNSSNSN

4

Sounds like just what you said - storing the bits as “|” instead of “-”

The advantage to this is that you get the same magnetic field strength for the bit, but with only the area of the vertical bits instead of the area of the horizontal bit.

Think of a bar magnet standing on end as opposed to laying on its side. The analogy isn’t realyl quite right since the bar magnet has the poles at the ends instead of on the top and bottom like in a hard disk, but you can see the savings in surface area.

Yes, the volume will quite likely stay the same - the surface area will change, though, and that’s the important thing. The limiting factor in reading data from a HD is the speed at which you can bring individual bits past the read/write head. Bits that use a smaller amount of surface area can be placed closer together. With the bits closer together, can read more of them per second without changing the rotational speed of the disk.