Formatting dvd's

Greetings

Is there some dvd’s that need to be formatted before burning, and some that come pre-formatted? I ask because I bought Imation discs [DVD+R:MBIPG101-R05-001] and noticed that Nero doesn’t show a formatting step during burning them.

And why all ss/sl DVD’s say 4.7gb on their covers, while they only have a capacity of 4483mb? does formatting take that much (4812-4483=329mb)?

Only DVD±RW need to be formatted, regarding the amount its how they work out the capacity of the disc has nothing to do with formatting it.

Thanks for the clarification. So why don’t they say 4.3gb on th box? what do they mean by 4.7gb? what does it refers to?

It’s a confusion within marketing. From the Wikipedia:

"Facts

[ul]
[li]As of 2007, most consumer hard drives are defined by their gigabyte-range capacities. The true capacity is usually some number above or below the class designation. Although most manufacturers of hard disks and Flash disks define 1 gigabyte as 1,000,000,000 bytes, most computer operating systems calculate a gigabyte by dividing the bytes (whether it is disk capacity, file size, or system RAM) by 1,073,741,824. This distinction is a cause of confusion, especially for people from a non-technical background, as a hard disk with a manufacturer rated capacity of 40 gigabytes would have its capacity reported by the operating system as only 37.2 GB.[/li][/ul]

[ul]
[li]The human genome contains 0.791175 GB of data (the 3.1647×109base pairs[4] represented as 2-bits).[/li][/ul] Gigabytes in different products

[ul]
[li]A DVD-5 format disc is capable of storing 4.7 gigabytes, or roughly 4.38 gibibytes. A DVD-9 is capable of storing 8.5 gigabytes, or roughly 7.92 gibibytes.[/li][li]One gigabyte is roughly equal to 18 hours of (http://en.wikipedia.org/wiki/MP3) music (at 128 kbit/s).[/li][li]One gigabyte is roughly equivalent to 11 hours, 40 minutes of Flash video (at 450x370).[/li][li]Most 6th generation and all 7th generation game consoles have game discs that are around 1 GB or more: Dreamcast (1.1 GB), GameCubePlaystation 2, Xbox, Xbox 360, and Wii (8.5 GB), and Playstation 3 (50 GB) (1.5 GB),[/li][li]Dual-layer Blu-Ray Discs and dual-layer HD DVD discs can hold about 50 gigabytes and 30 gigabytes of data."[/li][/ul]

See: http://www.osta.org/technology/dvdqa/dvdqa6.htm

I agree only DVD+/-R need to be formated +or -R are not formatable disc and not to need too.