DVD recordable

Embedded Data: A DVD-R disk (also applies to DVD+R) which still has space available. Data is burned onto the disk with a writing laser.

DVD recordable and DVD rewritable refer to part of Optical disc recording technologies. DVD optical disc formats that can be recorded by a DVD recorder, (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, primarily for the distribution of home video. 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. Dyes give the data side of a disc a distinct color. 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 "minus" or DVD "dash")

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.^{[citation needed]}

DVD+R/DVD+RW (DVD "plus")

Developed by Philips and Sony with their DVD+RW Alliance. Introduced 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.

Michael Spath at CDfreaks analyzed the specifications of DVD-R/RW and DVD+R/RW formats and came to the conclusion that the DVD+R/RW format is superior to DVD-R/RW.^[1]

Multi-format drives can read and 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.

DVD write-once formats

• DVD-R
• DVD+R

DVD rewritable formats

• DVD-RW
• DVD+RW
• DVD-RAM

Speed

Drive speed	Data rate		Disc write time	Equivalent CD rate	Reading speed
1×	11.08 Mbit/s	1.385 MB/s	53 min	9×	8×–18×
2×	22.16 Mbit/s	2.770 MB/s	27 min	18×	20×–24×
4×	44.32 Mbit/s	5.540 MB/s	14 min	36×	24×–32×
5×	55.40 Mbit/s	6.925 MB/s	11 min	45×	24×–32×
6×	66.48 Mbit/s	8.310 MB/s	9 min	54×	24×–32×
8×	88.64 Mbit/s	11.080 MB/s	7 min	72×	32×–40×
10×	110.80 Mbit/s	13.850 MB/s	6 min	90×	32×–40×
16×	177.28 Mbit/s	22.160 MB/s	4 min	144×	32×–40×
18×	199.44 Mbit/s	24.930 MB/s	3 min	162×	32×–40×
20×	221.60 Mbit/s	27.700 MB/s	2 min	180x	32×–40×
24×	265.92 Mbit/s	33.240 MB/s	2 min	216x	32×–48×

Notes:

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

Capacities

Most DVD±R/RWs are advertised as having a capacity of 4.7 GB. However these DVDs seem to hold less than the stated 4.7GB because many manufacturers quote the capacity of a DVD using decimal prefixes instead of the binary prefixes used by some software. This can be confusing for many users. 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.^[2]

Format	Decimal Prefix	Binary Prefix
DVD±R	4.70GB	4.38GiB
DVD±RW	4.70GB	4.38GiB
DVD±R DL	8.55GB	7.96GiB
DVD-RAM	4.70GB	4.27GiB
DVD-RAM DL	9.4GB	8.75GiB
MiniDVD	1.46GB	1.36GiB
MiniDVD DL	2.66GB	2.48GiB

Longevity

See also: Optical_disc_recording_technologies#Longevity

According to a study published in 2008 by the Preservation Research and Testing Division of the U.S. Library of Congress, most recordable CD products have a higher probability of greater longevity compared to recordable DVD products.^[3]

References

1. ^ "Why DVD+R(W) is superior to DVD-R(W)". http://www.myce.com/article/Why-DVDRW-is-superior-to-DVD-RW-203/. Retrieved 2010-03-14. 
2. ^ osta.org
3. ^ CD-R and DVD-R RW Longevity Research