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Wednesday, March 5, 2008

Blu-ray Disc recordable

Blu-ray Disc recordable refers to two optical disc formats that can be recorded with an optical disc recorder. BD-R discs can be written to once, whereas BD-RE can be erased and re-recorded multiple times. Disc capacities are 25GB (23.31 GiB) for single layer discs and 50GB (46.61 GiB) for dual layer discs.[1]

As of January 2008, BD-R/RE drives up to 6x are sold for about US$400 and 2x single-layer BD-R discs,[2] with a capacity of 25 GB, can be found for as low as US$10. The theoretical maximum for Blu-ray Discs is about 12x, as the speed of rotation (10,000 rpm) causes too much wobble for the discs to be read properly. This is similar to the 20x and 52x respective maximum speeds of DVDs and CDs.

Version

There are three versions of rewritable Blu-ray Discs (BD-RE):[3]

Version 1.0

  • unique BD File System
  • not computer compatible

Version 2.0

  • UDF 2.5 file system for computer use
  • the use of AACS
  • BD-R Version 1.0 follows this specification

Version 3.0

  • camcorder (8 cm) discs added
  • backward compatible with Version 2.0
  • BD-R Version 2.0 follows this specification

Speed

Drive speed Data rate Single layer BD write time
1X[1] 36 Mbit/s 4.5 MiB/s 95 min.
2X 72 Mbit/s 9 MiB/s 47 min.
4X 144 Mbit/s 18 MiB/s 24 min.
8X 288 Mbit/s 36 MiB/s 12 min.
12X 432 Mbit/s 54 MiB/s 8 min.


Optical disc authoring

Optical media types

Standards
Further reading



A blank rewritable Blu-ray disc (BD-RE)
A blank rewritable Blu-ray disc (BD-RE)



http://en.wikipedia.org/wiki/Blu-ray_Disc_recordable

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