The problem is really the use of
decimal prefixes for
binary multipliers. This is tradition in
parts the computer field (not for transfer rates, for example- Gigabit Ethernet means 10^9) because the values are so close, but that doesn't make it any better. The use of proper
binary prefixes as advocated by the IEEE, e.g. G
iB (Gibibyte) for 2^30 bytes, equivalent to 1073741824 bytes or ca. 1.074 GB (1.074 * 10^9) would obviate the entire confusion (see the discussion starting about
here). You can't really fault the hard drive manufacturers for publishing larger numbers, especially since they're an SI standard- after all, they
are marketroids. The
IEEE document has some even more abstruse examples.
The SI prefixes are a valuable good- look at the confusion that can arise from the differing use of "billion" in North America (=10^9, a thousand million) and Europe (=10^12, a million million). These numbers are different enough that the variant usage is obvious. The binary quantities are close enough to the decimal ones, though, to cause the kind of grief evident here.
I've used the binary prefixes ever since I found out about them and encourage others to do so as well- be a part of the solution, rather than part of the problem.
Dodecahedron: your example should read "74.59236587 G
iB isn't roughly 80 GB in decimal form, it's roughly 75 G
iB", which is like saying 1" = 2.54 cm.
G