Kilo, Mega, Giga, Tera

index -|- end -|- home

From yocto - to yotta!

As you may know, Kilo, Mega, Giga, Tera, Peta are just 5 from a LONGISH list of prefixes, that denote powers of 10 ... but are also often used in a powers of 2 way ...

from : http://whatis.techtarget.com/definition/0,,sid9_gci499008,00.html
Found this nice TABLE, expressed as powers of 10, and powers of 2 (where applicable) ...

Prefix

Symbol(s)

Power of 10

Power of 2

yocto-

y

10 -24 *

--

zepto-

z

10 -21 *

--

atto-

a

10 -18 *

--

femto-

f

10 -15 *

--

pico-

p

10 -12 *

--

nano-

n

10 -9 *

--

micro-

m

10 -6 *

--

milli-

m

10 -3 *

--

centi-

c

10 -2 *

--

deci-

d

10 -1 *

--

(none)

--

10 0

2 0

deka-

D

10 1 *

--

hecto-

h

10 2 *

--

kilo-

k or K **

10 3

2 10

mega-

M

10 6

2 20

giga-

G

10 9

2 30

tera-

T

10 12

2 40

peta-

P

10 15

2 50

exa-

E

10 18 *

2 60

zetta-

Z

10 21 *

2 70

yotta-

Y

10 24 *

2 80

* Not generally used to express data speed

** lower k = 10 3 and upper K = 2 10

top

This is a smaller table, just giving powers of 2 ... and the decimal values ...
from : http://computer.howstuffworks.com/bytes6.htm

Name

Abbr.

Size

Kilo

K

2^10 = 1,024

Mega

M

2^20 = 1,048,576

Giga

G

2^30 = 1,073,741,824

Tera

T

2^40 = 1,099,511,627,776

Peta

P

2^50 = 1,125,899,906,842,624

Exa

E

2^60 = 1,152,921,504,606,846,976

Zetta

Z

2^70 = 1,180,591,620,717,411,303,424

Yotta

Y

2^80 = 1,208,925,819,614,629,174,706,176

Or yet another nice table, showing only powers of 10, with an 'interesting' powers of 1000! column ...
from : http://www.jamesshuggins.com/h/tek1/prefixes.htm

Kilo

1000 1

10 3

1,000

Mega

1000 2

10 6

1,000,000

Giga

1000 3

10 9

1,000,000,000

Tera

1000 4

10 12

1,000,000,000,000

Peta

1000 5

10 15

1,000,000,000,000,000

Exa

1000 6

10 18

1,000,000,000,000,000,000

Zetta

1000 7

10 21

1,000,000,000,000,000,000,000

Yotta

1000 8

10 24

1,000,000,000,000,000,000,000,000

top

It also gives some information on where these prefixes came from ... their etymology  ... we now use Kilo, Mega, Giga, in common language usage ... and Tera is moving in fast ... as the computer hardware, operating systems, and programs, devices, we use, continue to 'grow' ... imagine if you had a 1 Yotta Bytes (YB) drive ... yowie ;=)) ...

And I thought I was 'happy' with my current 120 GB, hard disk drive (at a cost of A$132, in April, 2005) ... which only 'shows' 111 GB total, in Windows XP (NTFS) ... did the manufacturer gip me by 9 GB? ... 

No, the advertised 120 GB is probably the 'decimal' total, representation ... using power-of-10 ... while the computer software shows the size, using the power-of-2, convention ... where 1K is 1,024, not just 1,000 ;=)) Well, that accounts for 3-4 GB ... I guess the 'missing-balance' is track formatting information, directory information, landing zone, etc ...

These 'prefixes' are used for files, drives, devices, sizes, with the word Byte, with a capital B, appended ... so we use KB, MB, GB, TB, etc ... since we are talking about bits, and bytes, the power of two convention is used ... that is, a Kilo Byte is 1024 bytes, not the exactly 1000, as it actually means on the above table ... this shift, from powers-of-10 to powers-of-2, begins some user confusion ...

However, the water really muddies when we talk about TRANSFER rates ... traditionally, we talk about BITS PER SECOND ... that is, things like 56 K Baud ... is very close to 56 K bits-per-second, often written as 56 Kbps ... Kilo bits per second ... note, lower case 'bps' convention ...

But since the public, in general, appeared to be more familiar with, or interested in, BYTES, rather than BITS ... a byte = 8 bits ... the transfer rates are sometimes, by some people, expressed as Bytes-per-second ... in some circles, in some 'definitions' ... like, 56 KBps, meaning 56 Kilo BYTES per second ... note the uppercase 'B' ...

These transfer speeds, either expressed as bits-per-second, or Bytes-per-second, sometimes get confused, and interchanged a bit ;=((... since it only depends on whether the 'b' is lowercase, or uppercase! ... an attribute not usually spoken in conversation ... it is quite hard for us to 'visualise' either bits, or Bytes ... they become just terms used, without a good understanding ...

On transfer speeds, I have set up a little download 'speed' test, for FUN, which expresses the transfer speed, three ways, like the following :-

1020 (994) Kbps (Kilo bits per second),
which is 128 (124) KB/s (Kilo Bytes per second) or
0.99609375 (0.970554215502546) Mbit/s (Mega bits per second)

It is certainly interesting as these little prefixes come into our lexicon ... and we strive to understand what they mean ... use them ... compare them ... relate to them! ... put them in common conversation ... ;=)) in 'strine', "yorta-get-a-Yotta-drive, mate!" ...

top

Other 'big-number' site visited :
googol and googolplex - try here for more about really BIG numbers ...
http://www.fpx.de/fp/Fun/Googolplex/
*or*
http://pages.prodigy.net/jhonig/bignum/
*or*
http://web.telia.com/~u66017486/ph51b.html
This latter 'green' site, tells it all ... showing the American-French versus English-German NUMBER divide over the naming convention ... it is easier to be a billionaire in America - 3 less zeros! ...  the American-French system is winning, I think ... and throws in Roman numerals ... and a base table, showing a decimal, binary, ternary, octal, hexadecimal table ... and a number converter at the bottom ...

To me, NUMBER ARE FASCINATING ... I love em all ...

top

checked by tidy  Valid HTML 4.01 Transitional