quantifiers

quantifiers:  In techspeak and jargon, the standard metric
   prefixes used in the SI (Syst`eme International) conventions for
   scientific measurement have dual uses.  With units of time or
   things that come in powers of 10, such as money, they retain their
   usual meanings of multiplication by powers of 1000 = 10^3.
   But when used with bytes or other things that naturally come in
   powers of 2, they usually denote multiplication by powers of
   1024 = 2^(10).

   Here are the SI magnifying prefixes, along with the corresponding
   binary interpretations in common use:

     prefix  decimal  binary
     kilo-   1000^1   1024^1 = 2^10 = 1,024 
     mega-   1000^2   1024^2 = 2^20 = 1,048,576 
     giga-   1000^3   1024^3 = 2^30 = 1,073,741,824 
     tera-   1000^4   1024^4 = 2^40 = 1,099,511,627,776 
     peta-   1000^5   1024^5 = 2^50 = 1,125,899,906,842,624 
     exa-    1000^6   1024^6 = 2^60 = 1,152,921,504,606,846,976 
     zetta-  1000^7   1024^7 = 2^70 = 1,180,591,620,717,411,303,424 
     yotta-  1000^8   1024^8 = 2^80 = 1,208,925,819,614,629,174,706,176 

   Here are the SI fractional prefixes:

     *prefix  decimal     jargon usage*
     milli-  1000^-1     (seldom used in jargon)
     micro-  1000^-2     small or human-scale (see {micro-})
     nano-   1000^-3     even smaller (see {nano-})
     pico-   1000^-4     even smaller yet (see {pico-})
     femto-  1000^-5     (not used in jargon--yet)
     atto-   1000^-6     (not used in jargon--yet)
     zepto-  1000^-7     (not used in jargon--yet)
     yocto-  1000^-8     (not used in jargon--yet)

   The prefixes zetta-, yotta-, zepto-, and yocto- have been included
   in these tables purely for completeness and giggle value; they were
   adopted in 1990 by the `19th Conference Generale des Poids et
   Mesures'.  The binary peta- and exa- loadings, though well
   established, are not in jargon use either -- yet.  The prefix
   milli-, denoting multiplication by 1000^(-1), has always
   been rare in jargon (there is, however, a standard joke about the
   `millihelen' -- notionally, the amount of beauty required to
   launch one ship).  See the entries on {micro-}, {pico-}, and
   {nano-} for more information on connotative jargon use of these
   terms.  `Femto' and `atto' (which, interestingly, derive not
   from Greek but from Danish) have not yet acquired jargon loadings,
   though it is easy to predict what those will be once computing
   technology enters the required realms of magnitude (however, see
   {attoparsec}).

   There are, of course, some standard unit prefixes for powers of
   10.  In the following table, the `prefix' column is the
   international standard suffix for the appropriate power of ten; the
   `binary' column lists jargon abbreviations and words for the
   corresponding power of 2.  The B-suffixed forms are commonly used
   for byte quantities; the words `meg' and `gig' are nouns that may
   (but do not always) pluralize with `s'.

     prefix   decimal   binary       pronunciation
     kilo-       k      K, KB,       /kay/
     mega-       M      M, MB, meg   /meg/
     giga-       G      G, GB, gig   /gig/,/jig/

   Confusingly, hackers often use K or M as though they were suffix or
   numeric multipliers rather than a prefix; thus "2K dollars", "2M
   of disk space".  This is also true (though less commonly) of G.

   Note that the formal SI metric prefix for 1000 is `k'; some use
   this strictly, reserving `K' for multiplication by 1024 (KB is
   thus `kilobytes').

   K, M, and G used alone refer to quantities of bytes; thus, 64G is
   64 gigabytes and `a K' is a kilobyte (compare mainstream use of
   `a G' as short for `a grand', that is, $1000).  Whether one
   pronounces `gig' with hard or soft `g' depends on what one thinks
   the proper pronunciation of `giga-' is.

   Confusing 1000 and 1024 (or other powers of 2 and 10 close in
   magnitude) -- for example, describing a memory in units of
   500K or 524K instead of 512K -- is a sure sign of the
   {marketroid}.  One example of this: it is common to refer to the
   capacity of 3.5" {microfloppies} as `1.44 MB' In fact, this is a
   completely {bogus} number.  The correct size is 1440 KB, that
   is, 1440 * 1024 = 1474560 bytes.  So the `mega' in `1.44 MB' is
   compounded of two `kilos', one of which is 1024 and the other of
   which is 1000.  The correct number of megabytes would of course be
   1440 / 1024 = 1.40625.  Alas, this fine point is probably lost on
   the world forever.

   [1993 update: hacker Morgan Burke has proposed, to general
   approval on Usenet, the following additional prefixes:

groucho
     10^(-30)
harpo
     10^(-27)
harpi
     10^(27)
grouchi
     10^(30)

   We observe that this would leave the prefixes zeppo-, gummo-, and
   chico- available for future expansion.  Sadly, there is little
   immediate prospect that Mr. Burke's eminently sensible proposal
   will be ratified.]