# Data Density

Following question driven by seeing a box of floppy discs in tech room.

Question: How large would the floppy disk have to be to hold a hard drive of content?

Facts:

• A floppy disk holds 1.44 MB
• The largest consumer hard drive is 2 TB

Size of a desk? room? building? field? town?

Extension 1: What about a CD or a DVD?

Extension 2: How small could the hard drive be if it only held a floppy disk of material?

any more?

## Revision: 10/1/10 (or 22 to CS geeks)

Answer!  Highlight the text below to find the answer to the first question.

The floppy disk with a size of 2 TB would have a radius of about 47 meters.

Here’s a picture showing how large it would be: http://twitpic.com/2tpar3/full

## 4 thoughts on “Data Density”

1. Good call. A good CS question could be to ask how many pits are possible on the CD. I know there is some kind of error correction, but I’m not sure the ratio of real data to raw data.

1. FYI, I’ve amended the original post with an answer to the first question.
Cheers.