RE: Meg vs. MB vs. M

["Janet Swisher" <swisher -at- enthought -dot- com>]

At 3:44 PM -0700 1/27/04, sarahv -at- edt -dot- com wrote:
>I've recently butted heads with the marketing person at my very small
>company over the use of the term "meg." On our product list, she uses
the
>term meg, as in "blah-blah board with 1 Meg Memory." I checked with the
>software engineers and they said meg always means megabyte. But then
the
>hardware engineers said no, when she says 1 Meg Memory, she means 1
>million 32-bit words (equal to four megabytes); however, in digital
>cameras, it's really 1,024,000 32-bit words. I said OK like I
understood
>what they were talking about . . .

Kim is correct that RAM is usually defined in terms of 8-bit bytes, and
(despite the official SI prefixes) "mega" is commonly used in the binary
sense of 2^20, so that a megabyte is 2^20 (8-bit) bytes.

However, when you're talking about disk space, many manufacturers use
"mega" in the decimal sense of 10^6. This enables them to claim on their
packaging that their disks hold more "megabytes" than the OS (using
binary megabytes) shows them as having.

(The reference to digital cameras was to "megapixels". In this domain,
"mega" is decimal, and "pixel" is however many bits it takes to
represent the smallest dot in the picture. Usually these days, pixels
are 32 bits. Ergo, 1 million 32-bit words.)

My question is, why are you asking the engineers what the marketing
person means? Why not ask her what she means? And isn't there an issue
of what is actually in the product?

Figure out what you've got, decide what units you're going to talk about
it in (keeping in mind all our sage advice :-), and then do the math. If
you want to be really clear, explain your notation in a footnote.

-------------------------
Janet Swisher
Technical Writer
Enthought, Inc.
1-512-536-1057