Editing Constant linear velocity (section)

==Zoned constant linear velocity==
[[Image:Zone clv.jpg|thumb|The Zone-CLV recording strategy is easily visible after burning a DVD-R]]
'''Zoned constant linear velocity''' ('''''ZCLV''''' or '''''Z-CLV''''') is a modification of CLV for high speed CD and [[DVD recorder]]s where a constant linear velocity is maintained until the next zone, when the speed is stepped up.   Early model recorders were CLV drives. The recording speed on such drives was rated in multiples of 150 [[KiB]]/s; a 4X drive, for instance, would write steadily at around 600 KiB/s. The transfer rate was kept constant by having the spindle motor in the drive vary in speed and run 2.4 times<ref name=OD-Diameter/> as fast when recording at the inner rim of the disc as on the outer rim. Some high-speed recorders use the zoned CLV method (ZCLV), which divides the disc into stepped zones, each of which has its own constant linear velocity. When the current zone is finished and the next zone is reached, the disc rotation will speed up, usually to the same angular speed as at the beginning of the previous zone.

At higher speeds, ZCLV offers a compromise between CAV, which enables faster [[seek time]]s, and CLV, which enables greater writing reliability. A ZCLV recorder rated at "52X", for example, would write at a 52X disc rpm on the innermost zone and then progressively step down to 20X disc rpm at the outer rim to keep the rate at which bits are recorded by the laser within a narrow range.<ref name=Z-CLV>[https://qpxtool.sourceforge.io/glossar.html#zone_clv QPxTool glossary – Zoned CLV]</ref><ref name=OSTA-ZCLV>[http://www.osta.org/technology/dvdqa/dvdqa4.htm Understanding DVD -Recording Speed] by [[Optical Storage Technology Association]] – Section: Zoned Constant Linear Velocity (ZCLV)</ref> This method is used for higher-speed [[CD-RW#Details|CD-RW variants]] due to the narrow writing speed range of rewriteable media.