DVD Media Question

[Jakob]

ok, not having read any of your posts I may well look like an ass.. but I'm going to lay it all out:
Mathematically speaking, a GigaByte is 1000 MegaBytes, a MegaByte is 1000 KiloBytes and a KiloByte is 1000 Bites.
In the world of computers, which natively use Base 2 math, things are somewhat different.... A GigaByte is 1024 or 2^10 MegaBytes, a Megabite is 1024 or 2^10 KiloBytes and a KyloByte is 1024 or 2^10 Bites.
Since Mathematically speaking, their claims to the space are true, they can legally slap 4.7GB on a 4.38GB disc.

now, your mathematically 4.7GB disc is computer terms 4 700 000 000 Bytes, 4589843 KiloBytes, 4482 MegaBytes, and finally, 4.38 GigaBytes.

 

[PsyMan]

He is evil, he is bastard, he sounds like an ass but he is RIGHT.

 

[smcd]

http://en.wikipedia.org/wiki/Kilobyte this explains it pretty well. Basically it came down to people who "knew about computers" understood that a kilobyte == 1024 bytes, and then when computers became more popular, people who knew numbers and not computers heard "kilo" and thought "oh, must be 1000"

 

[Eagle]

ok, not having read any of your posts I may well look like an ass.. but I'm going to lay it all out:
Mathematically speaking, a GigaByte is 1000 MegaBytes, a MegaByte is 1000 KiloBytes and a KiloByte is 1000 Bites.
In the world of computers, which natively use Base 2 math, things are somewhat different.... A GigaByte is 1024 or 2^10 MegaBytes, a Megabite is 1024 or 2^10 KiloBytes and a KyloByte is 1024 or 2^10 Bites.
Since Mathematically speaking, their claims to the space are true, they can legally slap 4.7GB on a 4.38GB disc.

now, your mathematically 4.7GB disc is computer terms 4 700 000 000 Bytes, 4589843 KiloBytes, 4482 MegaBytes, and finally, 4.38 GigaBytes.

So in a nutshell the answer to the original question...

Hard drives and DVDs use base 10 math for their capacity calculation and CDs and your computer uses base 2 math calculations. Which is why your computer sees CDs exactly as they are advertised but sees HD's and DVD's as less than what they are advertised.

 

[Jakob]

Eagle: yeah, I would imagine that the only reason that CDROM capacities are done in base 2(binary) math is becuase in the beginning, no one really expected personal cd burners, so the capacity wasn't a selling point, merely a technical sidenote.