Jethro <Wilson@somewhere.org> wrote:

> I notice there is always a great disparity between stated hard
> drive capacity and actual usable capacity after formatting.

Not if you use the right maths.

> Is there a chart or other paper anywhere showing maybe comparisons of
> this between drives, and maybe an explanation of why and how it happens?

The main problem is that the hard drive manufacturers state the size
in decimal GBs, 1,000,000,000 bytes because that is the SI standard.
Its often shown in binary GBs in the OS, 1,073,741,824 bytes.

You also lose a much smaller amount in the file structures, directorys etc.