CD-ROM drives

Most optical drives today are combo CD/DVD drives that support DVDs and all the CD formats: CD audio, CD-ROM, CD-R and CD-RW. The speeds of the drives are rated by their CD-ROM and DVD transfer rates. The original CD-ROM drive (1x) transferred data at 150KB per second. By doubling the spindle RPMs, the data transfer rate increased to 300KB/sec (2x) and so on. See CD-ROM and DVD drives.

CD-ROM      CD-ROMX Rating    Data Transfer Rate

      1x       150 Kilobytes/sec
      2x       300 Kilobytes/sec
      4x       600 Kilobytes/sec

      8x       1.2 Megabytes/sec
      10x      1.5 Megabytes/sec
      12x      1.8 Megabytes/sec
      20x      3.0 Megabytes/sec
      36x      5.4 Megabytes/sec
      40x      6.0 Megabytes/sec
      48x      7.2 Megabytes/sec
      50x      7.5 Megabytes/sec
      52x      7.8 Megabytes/sec

What Does 40x/12x/48x Mean?
CD drive ratings are designated with three speed numbers such as 40x/12x/48x or 40/12/48, as follows:

First X     /  Second X     /  Third X
  CD-R write  /  CD-RW write  /  CD-ROM read

A Lot of X's

This is the label from a Memorex combo CD/DVD drive. Each "X" number means X times 150KB for CDs and X times 1.39MB for DVDs.

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References in periodicals archive

Three top CD-ROM drives that have earned best buy ratings from PC World magazine are NEC's CDR-73M, Toshiba's TXM-3301E and Sony's CDU-7205 Laser Library.

Quenching storage thirst

Bassick High School in Bridgeport, Conn., utilizes a CD-ROM drive in its graphics arts lab.

Educational applications abound for optical drives

The same telephone directory that previously needed three or four CDs to hold it can now fit easily on a single 4.7GB DVD-ROM disk; and read-only DVD-ROM drives, which cost only about $100 more than CD-ROM drives, can also read CD-ROMs and CD-Rs and CD-RWs.

Why The CD Tower Crumbled

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