Storage capacity of dvd-r

406lx · Member Joined: 21 Feb 2002

What is the storage capacity of a dvd-r. I know it says 4.7gb but can u really get this much on it as looking at dvd-r guides give the capacity at about 4.3gb.

Cheers

AntnyMD · Member Joined: 08 Jun 2001 Location: Silver Spring, MD USA

4.7gb on a DVD-R is equivalent to 4.3gb on a hard disk. The sectors are measured differently on each.

khelms · Member Joined: 08 Feb 2002

I don't think it's a matter of sector size, but one of terminology.
Kilobytes, Megabytes, and Gigabytes have traditionally been defined as 2 to the 10th, 20th, and 30th power by the computer industry. For some reason, the storage manufacturers that make hard drives and DVD-Rs have decided to use 1,000,000,000 for GB, instead of 1,073,741,824. Maybe they figure it's easier to remember and it has the additional (unintended, I'm sure) effect of making their products look bigger. That's why when you buy a 30GB hard drive and install it, you only see 27.9GB of disk space under Windows. Microsoft uses the traditional 2 to the 30th power definition of GB. If you divide 4,700,000,000 by 1,073,741,824 you get, surprise, 4.377.