PCMech Forums - View Single Post - DVD-Disc size?

RJ · 12-25-2002, 08:15 AM

Hi,

it's because the DVD manufacturers use the same wrong number for advertisement as the hard drive manufacturers do.
They calculate with 1000 instead of 1024. The result is:

4,7 GB -> 4700 MB -> 4700000 KB -> 4700000000 Bytes

Now, using 1024 you can calculate the real capacity:

4700000000 Bytes = 4589843,75 KB = 4482,269 MB = 4,377216 GB.

So 4,377 GB is the real capacity of a recordable DVD. Also look at the MB size: 4482. If you ever burned a data DVD using Nero, you will notice that the capacity mark is a few pixels right of 4480 MB.

The same calculation works for hard drive, if you wonder why for example a 120 GB drive shows up with 115 GB in Windows (Windows always displayes the correct size).

RJ

12-25-2002, 08:15 AM	#2
RJ Member (14 bit) Join Date: Feb 2000 Location: Offenbach/Main (Germany) Posts: 8,485	Hi, it's because the DVD manufacturers use the same wrong number for advertisement as the hard drive manufacturers do. They calculate with 1000 instead of 1024. The result is: 4,7 GB -> 4700 MB -> 4700000 KB -> 4700000000 Bytes Now, using 1024 you can calculate the real capacity: 4700000000 Bytes = 4589843,75 KB = 4482,269 MB = 4,377216 GB. So 4,377 GB is the real capacity of a recordable DVD. Also look at the MB size: 4482. If you ever burned a data DVD using Nero, you will notice that the capacity mark is a few pixels right of 4480 MB. The same calculation works for hard drive, if you wonder why for example a 120 GB drive shows up with 115 GB in Windows (Windows always displayes the correct size). RJ __________________ All's right with the world when your PC is working right. Last edited by RJ; 12-25-2002 at 08:17 AM.