Messages in this thread | | | Date | Tue, 28 Aug 2001 23:45:21 +0200 | From | Guest section DW <> | Subject | units - was: Re: Determining maximum partition size... |
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On Tue, Aug 28, 2001 at 01:53:29PM +0100, Anton Altaparmakov wrote:
> > > I thought maybe Linux set 1MB=1000k but that doesn't seem to case.
> >Well, 1 M = 1000 k by definition of the SI system of units. > >This has nothing to do with Linux. > > While it is true that M = 10^6 and k = 10^3, surely that doesn't apply to > byte quantities?!? At least I have always interpreted 1 Megabyte = 1024 > kilobytes = 1024*1024 bytes
Ah, an old discussion - I imagine it must have occurred here a few times. Anyway: k is the prefix for 1000, M is the prefix for 1000000. Always.
But there is a natural sloppiness, where people round numbers when either the precise size is unimportant, or is clear from the context. If xyzzies come in boxes of 27 and I say that I bought a hundred xyzzies then that probably means that in fact I bought 108.
Thus, our old PDP8 with 4k of memory had 4096 12-bit words, that is, 6 KiB in modern terminology.
You see two very different situations here: "precise size is unimportant" and "precise size is clear from the context". When someone says that she bought a 10 GB disk I will assume that the precise size is somewhere between 9.5 and 10.5 GB. This is the "rounded" case. When someone says that she bought a 32 MB SIMM I will assume that this was 32 MiB, that is, 2^25 bytes, since, unlike disks, memory modules tend to come in power-of-two units. This is the "clear from the context" case.
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