DVD Storage capacity

[Potatoman]

Why do i never get no where near 4.7Gb on one blank DVD? Its always just over 4Gb rather that nearly 5Gb.

[fo3nix]

because the manufacturers are allowed to quote quantities in the decimal system, whereas computers use the binary system.

in decimal, 1GB = 1,000,000,000 bytes
in binary, 1GB = 1,073,741,824 bytes (1024^3)

thus, 4.7GB / 1,073,741,824 bytes = 4.3772161006927490234375GB.

Thus you only actually get 4.377GB to play with.
The same happends with other forms of storage media, such as hard drives.

[Quicksilver]

Great answer fo3nix. I've always wondered about this too (regarding  hard drive space). Now I know. Thanks.

[Potatoman]

Thanks foryour help on that, fo3nix.

[fo3nix]

Glad it helped someone :)