Bits and Bytes

  • Thread starter Thread starter David Sworder
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David Sworder

I've searched the Internet and have come up with contradicting answers
so I'll put this question to you. If a line is rated as 1.5 Mbps (megabits
per second), how many bits per second is this?

a) 1.5 * (1000^2)=1,500,000

or

b) 1.5 * (1024^2)=1,572,864

I realize that due to protocol overhead, the actual transmittal of data
bits is far less, but that's not what I'm getting at. My concern is: Do you
use the magic "1024" number in calculations dealing with bits, or does that
only apply to bytes?

David
 
b = bit
B = Byte (8 bits)
k = kilo (1000)
K = Kilo (1024)
m = mega (1000)
M = Mega (1024)

Since 10 based numbers (decimals) are easy to work with for people, we use
them.
Computers, on the other hand use binary numbers.

So kb, Kb and KB will all mean different things.
According to the theory Mbps should use 1024 but do all ISPs use 1024 or do
some of them scam you and use 1000 instead? You make the call.
 
If you have a 1.5 mbps connection, then that is equal to

1.5 * 1024 = 1536 kilo bits

If your downloading files with internet explorer, it will display transfere
speeds in kilo bytes and not kilo bits (same with most other software, ftp
etc). Since there a 8 bits in a byte, divide 1536 by 8 to convert the bits
into bytes.

1536 / 8 = 192 kilo bytes

so baically, when your downloading files, your maximum throughput will be
displayed at 192 kb /second
 
Thanks, guys. This explanation seems to match what I've been reading
elsewhere, but I'm still confused as to WHY we ('we' the computer people)
use this odd method to measure memory. I understand that a kilobyte is 2^10,
mega is 2^20, giga is 2^30, etc. and I understand that computers are binary
machines and therefore deal with a base-2 system -- but why did we as
*humans* decide to use these odd definitions of K, mega, giga, etc? In other
words, why not define a kilobyte as 1,000 bytes, a megabyte as 1,000,000,
etc? After all, the computer itself doesn't have a concept of "K." "K" is
just a human term, so why not use a human 10-based system to describe it?

David
 
Make that 192Kb/sec and we have a deal ;-)

gareth said:
If you have a 1.5 mbps connection, then that is equal to

1.5 * 1024 = 1536 kilo bits

If your downloading files with internet explorer, it will display transfere
speeds in kilo bytes and not kilo bits (same with most other software, ftp
etc). Since there a 8 bits in a byte, divide 1536 by 8 to convert the bits
into bytes.

1536 / 8 = 192 kilo bytes

so baically, when your downloading files, your maximum throughput will be
displayed at 192 kb /second
Click to expand...
 
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