DVD recordable

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DVD recordable and DVD rewritable refer to DVD optical disc formats that can be recorded (written, "burned"), either write once or rewritable (write multiple times) format written by laser, as compared to DVD-ROM, which is mass-produced by pressing. DVD recordable is a general term that refers to both write-once and rewritable formats, whereas DVD rewritable refers only to rewritable formats.

Like CD-Rs, DVD recordables use dyes. Depending on the intensity of the laser, the reflective property of the dye on a particular spot will determine whether it is a peak or a valley representation from pressed DVD. Also because of the dyes, it gives the disc those distinct colors on the shiny side. Dyes are also the reason playback is not guaranteed. Their reflective properties are not as good as with stamped DVDs that commonly have aluminum as the reflective layer.

Recordable DVDs are divided into three incompatible camps:

DVD-R/DVD-RW (DVD "dash" (or DVD "minus" in the UK and Europe)): First DVD recordable format released in the market. Developed by Pioneer and backed by the DVD Forum. Has broader playback compatibility than the "+" especially with much older players. The dash format is based on an older CD-R/RW format for easy upgrade or migration for disc manufacturers.
DVD+R/DVD+RW (DVD "plus"): Developed by Philips and Sony with their DVD+RW Alliance. Came out after the "-" format.
DVD-RAM: As RAM stands for Random Access Memory, it works more or less like a hard-drive and was designed for corporate back-up use. Can only be read in drives that are DVD-RAM compatible. DVD Forum backs this format.

Multi-format drives can read (write) more than one format; e.g., DVD±RW (DVD plus-dash rewritable) is used to refer to drives that can write/rewrite both plus and dash formats, but not necessarily DVD-RAM.

DVD recordable media are sold in two standard sizes, a standard-sized 12cm size for home recording and computer usage, and a small 8cm size (sometimes known as a miniDVD) for use in compact camcorders and the like.

1 DVD write-once formats
2 DVD rewritable formats
3 Speed
4 Capacities
5 External links

[edit] DVD write-once formats

DVD-R
DVD+R

[edit] DVD rewritable formats

[edit] Speed

Drive speed	Data rate		Disc write time	Equivalent CD rate	Reading speed
1x	11.08 Mbit/s	1.32 MB/s	53 min	9x	8x-18x
2x	22.16 Mbit/s	2.64 MB/s	27 min	18x	20x-24x
4x	44.32 Mbit/s	5.28 MB/s	14 min	36x	24x-32x
5x	55.40 Mbit/s	6.60 MB/s	11 min	45x	24x-32x
6x	66.48 Mbit/s	7.93 MB/s	9 min	54x	24x-32x
8x	88.64 Mbit/s	10.57 MB/s	7 min	72x	32x-40x
10x	110.80 Mbit/s	13.21 MB/s	6 min	90x	32x-40x
16x	177.28 Mbit/s	21.13 MB/s	4 min	144x	32x-40x

Notes:

DVD 1x actual spin is 3 times that of CD 1x
Disk write time in table does not include overhead, leadout etc

[edit] Capacities

A DVD advertised as 4.7 GB may seem to hold less than that because manufacturers quote the capacity of a writable DVD disc using decimal prefixes rather than the binary prefixes used by some software. This can be confusing. While a 4.7 GB DVD can store 4.7 billion bytes [4,700,000,000 bytes ÷ 1000 B/kB = 4,700,000 kB ÷ 1000 kB/MB = 4,700 MB ÷ 1000 MB/GB = 4.7 GB], using binary prefixes the same capacity is roughly 4.38 GiB [4,700,000,000 bytes ÷ 1024 B/KiB = 4,589,844 KiB ÷ 1024 KiB/MiB = 4,482.27 MiB ÷ 1024 MiB/GiB = 4.38 GiB]. [1]

Mini-DVDs sold for use with camcorders generally have a capacity of approximately 1.7GB.