What is a gigabyte

Please tell me this ; what is a gig ? OR is it 1000 kb ? , in
otherwords
IS 1.2 gig the sames as 1200kb , or something else ? , like 100,000kb ,
I need to know so I get the correct processor for my pc , Phil

Dave Mayall...

No,

1.3 GB = 1331.2 MB
1.4 GB = 1433.6 MB

Jeff...

A unit of computer memory or data storage capacity equal to
1,024 megabytes (230 bytes).

Peter Duncanson...

I suggest the fault lay with the scriptwriter, not the actors. The
script should have been written the way it was intended to be read using
normal words. Using specialist notation is just asking for trouble.

Father Ignatius...

Tutor the power eighty.

One billion bytes. (U.S. Billion - 1,000 million)

Steve W. Jackson...

What? What's the "230 bytes" about? What's a "U.S." anything got to do

msb...

See below.

msb...

Just a way of referring to the "small" billion (1,000,000,000) as opposed
to the "large" billion of 1,000,000,000,000.

Dennis Lee Bieber...

US UK
thousand thousand
million million
billion thousand million (as I recall)
trillion billion

msb...

Simple. The 30 was supposed to be a superscript -- perhaps the message
was composed in HTML and then flattened to normal text with the loss of
the ^{tag. It's 2^30 bytes. The exact value is 1,073,741,824.

This is the common usage of "gigabyte" in computing, even though it

Peter Duncanson...

Except when hard disks are being bought and sold, in which case 1GB =

1,000,000,000 bytes.

The PC I'm using at the moment has two disks each with a nominal

capacity of 80GB. According to MS Windows the actual capacities are:

81,936,580,608 bytes 76.3GB

80,004,153,344 bytes 74.5GB

T.M. Sommers...

Some disk space is lost to file system overhead.

Peter Duncanson...

That is true. However, the two disks were advertised and sold as 80GB

disks. The two capacities quoted in bytes are approx 80GB where Giga =

1,000,000,000,000. The values given as 76.3 and 74.5 are representations

of those numbers of bytes using giga = 1,073,741,824.

trio...

Peter, I'm sure you didn't mean to confuse matters further by typing

three extra zeroes.

Peter Duncanson...

Quite right. That's three zeroes and one comma to be put back into the

box for reuse.

Steve W. Jackson...

Not so. It's simply that the gigabyte to which packaging refers is

indeed 1,000,000,000 bytes rather than what we computer geeks (and our

computers) use, which is based on the earlier cited premise that 1,024

bytes is one KB, and on upward.

Spehro Pefhany...

You can calculate the second number from the first simply by dividing

by 2^30 (and rounding to a single decimal place).

81,936,580,608/2^30 = 76.309387207031250

80,004,153,344/2^30 = 74.509674072265625

ObAUE: Dimensional analysis is left as an exercise. In the olden days

they sometimes advertised the unformatted capacity of storage media.

Best regards,

Spehro Pefhany

annoys some people because "giga-" usually means exactly a billion.}

with this?

Denis Beauregard...

No idea for the 230, but keep in mind that in French, we have:

1 million = 1,000,000
1 milliard = 1,000,000,000
1 billion = 1,000,000,000,000

while in English:

1 million = 1,000,000
1 billion = 1,000,000,000

Hairy Lethal...

Almost the same in Scandinavia, except they are spelled differently in
Sweden:

1 miljon = 1,000,000
1 miljard = 1,000,000,000
1 biljard = 1,000,000,000,000

Lars Enderin...

No, biljard is the game of billiards. In Sweden, we use 1 biljon=10^12,
and we are consistent: triljon = 10^18, kvadriljon = 10^24, etc - six
more zeros per level starting with biljon.

Hairy Lethal...

Are you all wrong? A Megabyte can have several interpretations, consider:

1 kilobyte = 1024 bytes - Ok!

1 Megabyte = 1024 kilobytes. This can be interpreted as:
1,000,000 bytes
or 1,024,000 bytes (1000 x 1024 bytes)
or 1,048,576 bytes (1024 x 1024 bytes)

jgh...

But you've already defined 1 kilobyte as 1024 bytes, so if you
define 1 Megabyte as 1024 kilobytes, then that automatically
defines 1 Megabyte as 1024 * 1024 bytes.

My house style is:

The single letter 'K' is a unit being 1024 bytes.
The single letter 'M' is a unit being 1024*1024 bytes.
The single letter 'G' is a unit being 1024*1024*1024 bytes.
32K is 32768 bytes. 2G is 2147483658 bytes.

The prefix 'k-' is a multiplier meaning 1,000*.
The prefix 'M-' is a multiplier meaning 1,000,000*.
The prefix 'G-' is a multiplier meaning 1,000,000,000*.
32km is 32,000 metres. 2GW is 2,000,000,000 Watts.

1 Gigabyte = 1024 Megabytes. Then surely this can be interpreted as:
1,000,000,000 bytes
or 1,024,000,000 bytes
or 1,048,576,000 bytes
or 1,073,741,824 bytes

1 Tetrabyte = 1024 Giggabytes. Then surely this can be interpreted as:
1,000,000,000,000 bytes
or 1,024,000,000,000 bytes
or 1,048,576,000,000 bytes
or 1,073,741,824,000 bytes
or 1,099,511,627,776 bytes (almost 10% difference)

Computing is such an exact subject!

No idea for other languages, but perhaps someone who knew that the
billion can be defined differently depending on the language.

Denis Beauregard...

The size you need will really depend on heavy use you make or
not.

I purchased a new hard disk last week end, for a laptop. I had
the choice between 40 and 80 gig, which are roughly 40,000,000,000
and 80,000,000,000 characters.

For a typical genealogist that is using his/her computer for data
entry and to have some photos on the computer, 20 or 30 gig are
quite enough and in 2006, it can be less than the smaller disk
you can find anyway.

But if you are a heavy genealogist, download every computer book
on the net, take photos of every record, every book you have in
your home (in case you need them when travelling), etc., then you
may need more. For example, all Quebec's vital records are about
1,000 gig (for 2300 reels). I was told that rootsweb had 3,000 gig
of data space 5 years ago.

For comparison:

1 floppy disk = 0.0014 gig (1.44 meg)
1 full CD-ROM = 0.7 gig
1 full DVD-ROM = 4.7 gig
1000 photocopies legal size = 0.5 gig to 2 gig (roughly)

The exact value of 1 gig is something else. But anyway, a hard disk
is some plates x some tracks x some bytes and this is usually not a
flat number. 1 gig can be 0.9.

Dave Mayall...

OK, after dozens of posts looking at the difference between 1000 and 1024
multipliers in determining the number of bytes, we should probably return to
the question!

It appears that you are actually talking about the *PROCESSOR*, rather than

Dave Mayall...

Well, if they describe a processor as 1333MB, they are using the wrong
units. If they describe it as 1333MHz, then it is exactly the same as
1.333GHz/Gig

memory/disk.

Whilst you will see "gig" used when talking about both things (because
that's what techies do), it is actually being used as a contraction of two
different terms;

1) Gigabyte (2^30 bytes) - a measure of the amount of disk/memory storage
2) Gigahertz (10^9 clock pulses per second) - a measure of processor speed

Each instruction passed to a CPU takes a certain number of clock cycles to
run (typically 1-6 cycles, depending on the instruction), so a 2GHz
processor (of the same model) will run programs twice as fast as a 1GHz
processor.

Dennis Lee Bieber...

Only if the entire program and data can fit within the processor
cache.

Doesn't do much good to have a really fast CPU if every other memory
reference has to flush the cache and load from slow RAM (what is current
top-end -- an 800MHz front-side bus with double-data-rate access?). A

John O'Flaherty...

He's just trying to terafy everyone.

Peter Duncanson...

Including myself.

program that is comparing the first byte from each Megabyte of memory is
going to be limited to the memory access speed, even if the code itself
is totally within the fast cache...

Dave Mayall...

Indeed there are limits, but I'm trying to keep it simple.

I can talk about predictive fetch and stuff, but it's too involved for the
question!

Peter...

The mega, giga, tera prefixes are used in the SI system to denote multiples
of 1,000.
That is, a MJ is 1,000,000 J and 1 MW = 1,000,000 W.
Similarly, 1 GB = 1,000 MB.

If you want to talk in multiples of 1,024, you should use the prefixes mebi,
gibi, tebi, etc.

More detail at wikipedia ...

Steve Hayes...

1 phone = 1000 microphones

1 megaphone = 1000 phones.

1 Gigabyte = 1024 Megabytes

1 Megabyte = 1024 Kilobytes

1 Kilobyte = 1024 bytes

1 byte = 8 bits (usually)

1 bit = 0 or 1

Jerald H. Mathews...

kilo - 10 with 3 zeros
mega - 10 with 6 zeros
giga - 10 with 9 zeros
tera - 10 with 12 zeros
peta - 10 with 15 zeros
exa - 10 with 18 zeros
zetta - 10 with 21 zeros
yotta - 10 with 24 zeros
[ That is yotta not Yoda 8-) ]

Jerald H. Mathews...

Oops, these should read"

kilo - 1 with 3 zeros
mega - 1 with 6 zeros
etc...

Jerry M.
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