Comments on: Perpendicular recording: Why it matters

Hard-drive capacity is running up against physical limits, says Hitachi Global Storage CEO Jun Naruse, but an old technology may save the day.

but what about speed?

Increased density is great, but is anything being done to significantly speed up efficiency so that CPUs aren't waiting on disk I/O?

[br77575]

Re: but what about speed?

More data in a single revolution will automatically increase the speed.

Get perpendicular flash video

Try this animated flash video explaining perpendicular recording:

http://www.hitachigst.com/hdd/research/recording_head/pr/PerpendicularAnimation.html

[Stating]

IBM Had This 40 Years Ago

Everything old is new again. A number of IBM disk drive models back in the 60's supported cylinder recording (perpendicular). Data was written across multiple platters simultaneously, top to bottom then left to right to reduce rotational delay.

http://www.ibm1130.net/functional/DiskStorage.html
Data Organization

The disk access mechanism, located in the disk drive, is moved back and forth by programmed commands and can be placed in any one of 203 positions, from a point near the periphery of the disk to a point near the center of the disk. At each position, the heads can read or write in a circular pattern on both surfaces of the disk, as it revolves. The circular patterns of data are called tracks. The track on the upper surface of the disk and the corresponding track on the lower surface, both of which can be read or written while the access mechanism is in the same position, are called a cylinder.


Keith
www.techcando.com

You mis-understand completely....

Perpendicular recording has nothing to do with how multiple heads search for the data over multiple disks. It is the fundemental way that the data is magnetically stored on the disk. Imagine it this way.... Think of a bunch of people laying down within one lane of a running track (the HDD disk). Imagine that your job is to go along the line of people and note the orientation of each person's head/feet (the HDD head). So you are going along counting "head, feet, feet, head, feet, head, head, feet" (in HDD terms - positive, negative, negative, positive....).
Now, let's say you want to add more people to that given track lane (increase HDD areal density). So you tell everyone to move closer to each other - move your feet closer to the next person's head. Well, you can only scrunch everyone so close together until feet start overlapping heads, and you are no longer able to quickly walk by and count head/feet order (HDD data integrity loss).
So you think, hmmmm....if I got everyone to stand up instead of laying down (perpendicular), then I just have to count who are standing on their heads and who are doing handstands.
OK, my analogy starts to get a little silly here, but you get the idea. Hope this helps. And yeah, I'm in the HDD industry.

This is not the same

This is not the same as the old IBM technology, this is actually affecting the way the bits are arranged on a single platter. instead of a byte being arranged like so -------- it will now be arranged like ||||||||.