See, this is what happens when two nerds get married and have little boys.

Friday, November 21, 2008

Geek Morsel

The more you understand about technology, the cooler it gets. I think most of our readers know that you can put a LOT of pictures, music, and email on a computer, but humor me while I explain how amazingly cool that feat is.

All of that data is stored on a hard disk. Inside that hard disk are a few, well... disks (as in flat, round plates) called platters. They're stacked vertically, and spin very quickly. Similar to a record player, data is stored in rings (records use spirals), and a head reads data from the platter, moving toward the center of the platter and back out again depending on where the data is (just like you can move a record player head to skip to different parts of a record). So there is a platter, always spinning, and a head moving in and out to read data as it passes underneath.

The interesting part about this all this is the scale! I first learned this in a class a few years ago, but saw it again today in Tom's Hardware:

"The dimensions of the head are impressive. With a width of less than a hundred nanometers and a thickness of about ten, it flies above the platter at a speed of up to 15,000 RPM, at a height that’s the equivalent of 40 atoms. If you start multiplying these infinitesimally small numbers, you begin to get an idea of their significance.

Consider this little comparison: if the read/write head were a Boeing 747, and the hard-disk platter were the surface of the Earth:

* The head would fly at Mach 800
* At less than one centimeter from the ground
* And count every blade of grass
* Making fewer than 10 unrecoverable counting errors in an area equivalent to all of Ireland."

You can look at scale another way: a nanometer is one-billionth of a meter. According to this link a germ is about 1000 nanometers large. That hard drive head is a tenth the width of a germ. Next time you feel like your computer is taking too long to do something, think of a Boeing 747 flying at 800 times the speed of sound counting blades of grass!


Amanda and Adam Walsh said...

Neat! Neat idea...amazing technology we take for granted, huh?

Shelly said...

Very informative! Great when they work right! When they don't..... no so great!