Re: PROBLEM: KB->KiB, MB -> MiB, ... (IEC 60027-2)

From: Bodo Eggert
Date: Mon Jan 22 2007 - 17:27:36 EST


On Mon, 22 Jan 2007, Tony Foiani wrote:

> >>>>> "Jan" == Jan Engelhardt <jengelh@xxxxxxxxxxxxxxx> writes:
>
> Jan> For "F"s sake, when you gotta use abbreviations, then just use
> Jan> k=1000 and K=1024 already, b for bits and B for bytes. Problem
> Jan> gone.
>
> The one-letter abbreviations are identical to SI prefixes, except
> for "K", which is used interchangeably with "k" (in SI, "K" stands
> for the kelvin, and only "k" stands for 1,000).
>
> [...]
>
> BIPM (which maintains SI) expressly prohibits the binary prefix
> usage, and recommends the use of the IEC prefixes as an alternative
> (computing units are not included in SI).
>
> Some have suggested that "k" be used for 1,000, and "K" for 1,024,
> but this cannot be extended to the higher order prefixes and has
> never been widely recognised.
> -- http://en.wikipedia.org/wiki/Binary_prefix
>
> So if you continue insisting that "MB" is really 2^20 bytes, you're
> flouting the SI in at least two ways.

The use of SI is not even accepted on bytes.
See <URL:http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf>.

Therefore "MB" is undefined in the SI world, and 2^20 B in the IT world.

> I'd expect that from an USAian,
> not a German. ;-> (To be clear, I *am* a USAian, and I really
> desperately wish this country were metric...)

I'd even prefer decimal hours, minutes and seconds.

> Some other gems from that article that haven't been covered in this
> thread:
>
> * CD-Rs are generally specified in MiB, but DVD-Rs in GB
> * CPU clocks are given in decimal

Hz is a supplementary SI unit.
--
"Those who would give up essential liberty, to purchase a little
temporary safety, deserve neither liberty nor safety."
-- Benjamin Franklin, Historical Review of Pennsylvania, 1759
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