Packaging lies over capacity

[Benjiman]

I've just bought an external hard drive which on the box says it is 500 Gb. Upon plugging it into my laptop and checking it says it has 104 Mb of used space and 465 Gb of free space.

Where are the missing 34 Gb?

And the space on USB stick I recently bought totals upto a Gb less than advertised.

Why isn't this false advertising?

[scotman]

Probably due to differing definitions of GB

[RATTER15]

I think the answer to this is along the lines of, it is a 500 gig hard drive however some PCs wont recognise certain figure in respect of hard drive space, so your laptop is actually giving you the wrong information, I'm sure chuck will explain this better than I did. Ive seen this occur a few times.

CHUCK!!!!!!!!!!!!

[MarkRae]

Nothing to do with what PCs can and can't recognise.

Put simply, PCs work in binary numbers, and 2^10 = 1,024. This figure is quite close to 1,000 so it is traditionally (but incorrectly) called a kilobyte. This implies that a kilobyte is 1,000 bytes, but it's not. This is further compounded by whether a megabyte is 1,000 kilobytes or 1,024 kilobytes. And so on.

See the Ambiguity section here for a more detailed explanation: http://en.wikipedia.org/wiki/Kilobyte

[ChuckFickens]

MR can explain just as well, if not better (He'll certainly do it with better grammar than me :) )

It's mainly as Mark said, you can add a little on due to formatting overhead too but that amount becomes negligible at 500GB drive size.

[RATTER15]

Thats exactly what I meant to say :-)