Anyone know why 8X+++ burners start burning at 4X

[pete2828]

I am just wondering if anyone knows why 8X to 16X burners start burning at the speed of 4X then increase toward the end of the disk. The top speed is only for like the last GB.

But, 4X burners burn start and end on 4X? why the difference? Is it a media issue?

[noki]

The dvd burner cannot spin fast in to cover the necessary space in the inner part of the dvdr to burn at a such a fast rate. but the angular velocity changes as the burner goes toward the edge of the disc (ie more of the dvdr is covered with each revolution)

[pete2828]

I know that the anugual velocity is lower at the beging of the disk than at the end. the point is that 4X DVD spin speed is equal to 1X CD spin speed at the same disk position. So DVDs natuaraly spin slower than CDs. So if DVDs were spun at the same RPMs of CD at the inner part of the disk the speed willbe much faster

[OmegaSupreme]

I think you are confused. DVDs have a higher rotational speed than CDs. A 1x CD-ROM rotates between 200-500 rpm, a 1x DVD-ROM rotates between 570-1600 rpm. Comparing data rates, a 1x DVD-ROM is equal to a 8x CD-ROM.

[ViRaL1]

9.

[KDH]

Z-CLV
Zone-Constant Linear Velocity, the disc(CD/DVD) is divided into zones. After each zone the write speed is increased

[TerminalVeloCD]

To clarify, if a DVD was written at 8x CLV (Constant Linear Velocity), the disc would be spinning at around 10,000rpm when the inner tracks are written. This would mean that the disc would be prone to shattering inside the drive and a high amount of stress would be placed on the internal components of the DVD writer. Therefore, when writing DVDs at speeds higher than 4x (or 6x on some models), drives adpot a different write strategy to keep the disc revolution speed down. One option for drive manufacturers is to use Z-CLV (Zoned Constant Linear Velocity), where a burn is divided up into two or more zones (or steps) with the slowest speed zone used on the inner tracks of a disc. Another option is for manufacturers to adpot a P-CAV (Partial Constant Angular Velocity) or CAV (Constant Angular Velocity) write strategy. Although faster and technically better in my opinion, P-CAV and CAV write strategies demand more programming by the drive manufacturers, because the write strategy is constantly changing due to the constantly rising speed.

Regards,
TerminalVeloCD

[garryheather]

I linked to some graphs demonstrating this here:

https://www.videohelp.com/forum/viewtopic.php?t=230126&highlight=