CAV - Constant Angular Velocity





Short for "Constant Angular Velocity". With CAV, the rotational speed of the media stays constant no matter on what position of the disk the optical pick-up head (PUH) is located. On the other hand the data transfer rate varys depending on the position of the data on the disk. If the PUH moves towards the center of the disc, the data transfer rate slows down; if it moves towards the outside, the transfer rate increases.



With this, the disc is written at a constant marginally increasing speed until it reaches it's maximum speed with coincides with the end of the disc.



[img]http://www.cdspeed2000.com/images/write_cav.gif[/img]



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P-CAV (Partial Constant Angular Velocity)



The disc is written to at an increasing speed until it reaches it's maximum and from then on the transfer rate remains constant. P-CAV drives are faster because they reach their maximum speed much earlier.



P-CAV is a combination of CLV and CAV.

The transfer rate increases until the drive reaches it's maximum speed (CAV). From that point the drive will slow down and the transfer rate will be constant (CLV).

Because P-CAV drives reach their maximum speed much sooner than CAV drives, the average transfer rate should be higher.





[img]http://www.cdspeed2000.com/images/write_pcav.gif[/img]



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Z-CLV (Zoned Constant Linear Velocity)



Most high speed recorders are using this technology. There are several CLV zones



Z-CLV is only used in the writing process and the way it works is that the drive is divided into a series of zones. After each zone, the write speed is increased until the last zone is burned at maximum speed.



[img]http://www.cdspeed2000.com/images/write_zclv.gif[/img]





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SONY 710A (16x) [same chipset with 12x dvdrw]

Write Strategy = CAV



*Liteon,Teac,Memorex (oem)







Benq DW1600 (16x)

Write Strategy = P-CAV



*Philip,Nu,Msi (oem)





PIONEER DVR-108 (16x)

Write Strategy = Z-CLV



* use NEC chipset , but different hardware with NEC3500A drive.





NEC ND-3500A (16x)

Write Strategy = CAV



* TDK 1616N , Asus, Aopen.. (oem)

SONY 710A (16x)


Benq DW1620 (16x)


PIONEER DVR-108 (16x)


NEC/TDK ND-3500A (16x)

SONY 710A 16x dvdrw


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Memorex F16 dvdrw (oem Sony)



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MSI DR16-B 16x dvdrw ( like benq dw1600 ??)



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PIONEER DVR-A08-J



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Benq DW1620





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Samsung TS-H552



http://www.cdrinfo.com/Sections/News/Detai...px?NewsId=10050

LG GSA-4160B








WRITE：
·DVD+R DL：2.4X CLV
·DVD+R：16X ZCLV
·DVD+RW 4X CLV
·DVD-R：8X ZCLV
·DVD-RW：4X CLV
·DVD-RAM：5X PCAV
·CD-R：40X ZCLV
·CD-RW：24X ZCLV

READ：
·DVD-ROM：16X CAV
·DVD+R DL：8X CAV
·DVD±R：10X CAV
·DVD±RW：8X CAV
·DVD-RAM：5X PCAV
·CD-ROM：40X CAV
·CD-R/RW：40X CAV
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NU DDW-163



Burn:
·DVD+R：16X
·DVD-R：16X
·DVD+RW：4X
·DVD-RW：4X
·DVD+R DL：2.4X
·CD-R：40X
·CD-RW：24X

READ:
·DVD-ROM：16X
·CD-ROM：40X