Constant linear velocity

Their rotation gradually decreases from 495 to 212 rpm to keep the disc moving past the read laser at 1.2 m/s (3.9 ft/s) (assuming 1:1 playback speed and Red Book encoding).

To accommodate the higher data transfer rates and random access requirements of modern CD-ROM drives, CAV systems are used.

This is because seek performance would be greatly affected during random access by the requirement to continually modulate the disc's rotation speed to be appropriate for the read head's position.

[2][3] This method is used for higher-speed CD-RW variants due to the narrow writing speed range of rewriteable media.

In the mid 1980s, Pioneer Electronics introduced the CAA scheme, where the rotation speed of the LaserDisc was lowered in steps.

Comparison of several forms of disk storage showing tracks (not-to-scale); green denotes start and red denotes end.
* Some CD-R(W) and DVD-R(W)/DVD+R(W) recorders operate in ZCLV, CAA or CAV modes.
Dimensions of a standard-size (12cm diameter) optical disc
The Zone-CLV recording strategy is easily visible after burning a DVD-R