## DVD drives - Computer Definition

Most optical drives today are combo CD/DVD drives that support all the DVD and CD formats. The speeds of the drives are rated by their DVD-ROM and CD-ROM transfer rates. The original DVD drive (1x) transferred data at 1.39MB per second, sufficient for movies. By doubling the spindle RPMs, the data transfer rate increased to 2.77MB/sec (2x) and so on.
**Nine Times the CD-ROM Rating**
Each DVD X is equivalent to roughly nine X's of CD speed because a DVD 1x is 1.39MB and a CD-ROM 1x is 150KB. See DVD player and CD-ROM drives.
**DVD-ROM Data**
**DVD-ROM Transfer Rate**
**X Rating (MBytes/sec)**
1x 1.39
2x 2.77
2.4x 3.32
4x 5.54
6x 8.31
8x 11.08
10x 13.85
12x 16.62
16x 22.16
18x 24.93
20x 27.70
22x 30.47
24x 33.24