Jeremy Portzer wrote:
On Thu, 2004-07-22 at 07:13, Brian Henning wrote:
Most companies see 300000mb as 300GB, but OSs see 300000 as 300000/1024 or
293GB..
Actually (for the sake of hair-splitting...), it's worse than that.
Marketers see 300,000,000,000 bytes as 300 GB, while OSes will see it as
300,000,000,000 / (1024 * 1024 * 1024) = 279.4 GB.
I remember reading somewhere that it's the difference between "300GB" and
"300 GB" but I'm not sure if that's true, and if it is I can't remember
which is which.
The unambiguous way to resolve this is to use different prefixes when
referring to the 1024 multiples. For examples, 300 GB = 279.4 GiB.
1 KiB = 1024 bytes, 1 MiB = 1024 KiB, 1GiB = 1024 MiB.
The Ki,Mi,Gi, prefixes are not officially part of the metric or US units
system but are beginning to see wider acceptance. The original document
on this subject is here: http://physics.nist.gov/cuu/Units/binary.html
. If you do a Google search on "Kibi Mebi Gibi" or something like that
you'll see many more informative articles.
I have to conclude that the drive manufacturers are "correct" when they
use the metric prefixes exactly as defined, K=10^3, M=10^6, G=10^9.
--Jeremy
Indeed - the drive manufacturers are "technically" in the right. The
catch is with computers it's always easier to deal in powers of 2 -
hence the 1024, being 2^10. Back when it was 1024 bytes, or 1024
kilobytes, people just assumed that it was "close enough" - but as this
discussion shows, when you scale that up a few orders of magnitude, the
difference is much more significant.
Aaron J.
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