# A CDE Definition

DVD drives

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

**A Lot of X's**

**Before/After Your Search Term**

Before | After |
---|---|

4K2K | 4xAGP |

4KRO | 5-4-3 rule |

4mm tape | 5 ATM |

4NT | 5 GHz |

4QAM | 5 GHz band |

4RU | 5 nines |

4S | 5-pin to 11-pin adapter |

4th generation language | 5.1 channel |

4U | 5.25 inch |

4x CD-ROM | 50 GbE |

**Terms By Topic**

Click any of the following categories for a list of fundamental terms.