Blu-ray Disc

Blu-ray Disc recordable

"Blu-ray Disc recordable" (BD-R) refers to two optical disc formats that can be recorded with an optical disc recorder. BD-Rs can be written to once, whereas Blu-ray Disc Recordable Erasable (BD-REs) can be erased and re-recorded multiple times. The current practical maximum speed for Blu-ray Discs is about 12× (54 MB/s). Higher speeds of rotation (5,000+ rpm) cause too much wobble for the discs to be written properly, as with the 24× (33.2 MB/s) and 56× (8.2 MB/s, 11,200 rpm) maximum speeds, respectively, of standard DVDs and CDs. Since September 2007, BD-RE is also available in the smaller 8 cm Mini Blu-ray Disc size.