[boardsurfer]

OK. I'm not completely stupid.
Here is what I know. 1000 bytes = 1 kb. Right? and 1000kb = 1 MB. Right?
Where the hell does a megabit fit into this?

[awaspaas]

A megabyte is 8 megabits.

[Thorin]

1 byte = 8 bits
1024 bytes = 1 kilobyte
1024 kilobytes = 1 megabyte

1024 bits = 1 kilobit
1024 kilobits = 1 megabit

So there's 1 048 576 bits in a megabit, or 8 388 608 bits in a megabyte. So yes, 1 megabyte is 8 megabits.

Why we use the two different sytems I have no bloody idea. It was probably do to with marketing really low bandwidth networking equipment (really old dial up modems and stuff) or something like that at a guess (that was a wild stab in the dark and may be completely wrong!)

[Ozmodiar]

So 54 Mbps is actually 6750000 Bytes per second, or 6.75 Megabytes per second. Right? Or am I way off here.

[Thorin]

54 Mbps is 6.75 megabytes per second, yep. Although you'd probably never actually get 6.75 megabytes per second through a 802.11g setup due to overheads, signal degradation and encryption etc.

[tooki]

Originally posted by boardsurfer:
OK. I'm not completely stupid.
Here is what I know. 1000 bytes = 1 kb. Right? and 1000kb = 1 MB. Right?
Where the hell does a megabit fit into this?

Note the abbreviations:

bit=b
byte=B

1000 bytes=1KB, not 1Kb.
1000 kb = 1Mb, not 1MB

1 byte=8 bits

So, 1000KB=8000Kb




Note also that there are "decimal" and "binary" kilo/mega/giga, etc.

In most computing applications (notable exception: hard drives), power-of-2 ("binary") multiples of 1024 are used: KB=1024 bytes, MB=1024x1024 bytes, GB=1024x1024x1024 bytes, etc

In all other fields, power-of-10 ("decimal") multiples of 1000 are used: K=1000, M=1000x1000, G=1000x1000x1000.

There's a new standard abbreviation system, which hasn't really caught on, which says that KB/MB/GB etc are for decimal multiples, and that KiB/MiB/GiB are for binary multiples.

e.g.:
1KB=1000 bytes
1KiB=1024 bytes

See http://physics.nist.gov/cuu/Units/binary.html for more info on this.

tooki

[boardsurfer]

whew. awesome, thanks guys.

[boardsurfer]

Originally posted by Thorin:
54 Mbps is 6.75 megabytes per second, yep. Although you'd probably never actually get 6.75 megabytes per second through a 802.11g setup due to overheads, signal degradation and encryption etc.

So would there wouldnt be much of a difference in performance if I used Airport vs. Airport Extreme, conected to a typical DSL modem. The Extreme performance would start to show through in file transfers and the like?

[itai195]

Originally posted by boardsurfer:
So would there wouldnt be much of a difference in performance if I used Airport vs. Airport Extreme, conected to a typical DSL modem. The Extreme performance would start to show through in file transfers and the like?

Yes, the Extreme would only be faster for internal network traffic. Even 802.11b (Airport) can easily handle ADSL bandwidth, which maxes out at 1.5 mbps downstream.

[Thorin]

Originally posted by boardsurfer:
So would there wouldnt be much of a difference in performance if I used Airport vs. Airport Extreme, conected to a typical DSL modem. The Extreme performance would start to show through in file transfers and the like?

Yup, spot on. Most broadband is measured in kilobits or megabits, so a 500Kb (0.5Mb) cable connection isn't going to put much of a dent in an 11Mb wireless connection.

For file transfers though you will notice the difference. If I need to transfer large files to my laptop I often plug it into the router with a wire so I can get the full 100Mb/s rather than be limited by the 54Mb/s of wireless.

[Link]

Remember to take into account signal strength and overhead when computing these numbers

6.7ish MB/sec is EXTREMELY optimistic on an airport extreme connection. So much so I doubt you'd normally get half that.

[opheim]

Just a small addon;

bits are normally used for defining speeds
bytes are normally used for defining size

Hence the use of kilobits and megabits in connection terms, and kilobytes, megabytes, gigabytes and so on when it comes to hard drives and other kinds of storage. The difference in acronyms is the size of the b. b=bits, B=bytes.

[boardsurfer]

Consider me edumacated! Thanks again.

[Xeo]

Originally posted by Thorin:
Why we use the two different sytems I have no bloody idea. It was probably do to with marketing really low bandwidth networking equipment (really old dial up modems and stuff) or something like that at a guess (that was a wild stab in the dark and may be completely wrong!)

Well, they aren't different systems. One is just a representative of a fixed multiple of another. A bit is a single 1 or 0. Generally this isn't enough to have any valuable information. However, ASCII is an 8 bit representation of the English alphabet, the numbers, and several additional characters. Back in the early days of computers, ASCII was all they used. I don't know the exact history, but I would guess that this is where the byte came in. A byte, being 8 bits, is enough to store a single character. So by measuring space in bytes, we can see how much real-world data can be stored on it.

Just a(n educated) guess.

[ginoledesma]

Originally posted by tooki:
There's a new standard abbreviation system, which hasn't really caught on, which says that KB/MB/GB etc are for decimal multiples, and that KiB/MiB/GiB are for binary multiples.

Well, they sound funny, too, and when you mention it to others, you're usually met with a blank or funny stare.

KiB is pronounced kibibyte, MiB as mebibyte, GiB, as gibibyte, and so on.

I wonder when this will catch on, if ever?