Why do DVD Recordable drives have such slow CD-R/RW burning?

[Coyote]

I'm curious why DVD drives have slow CD-R/RW burning speeds, compared to regular CD-R/RW drives. Is this some kind of marketing gimmick to slowly make the CD-R speeds faster, which makes people buy different drives? At least that's what I think. They already have the mechanism/technology to burn CD-R at up to 52x. So why can't they just "add-on" whatever laser is required to do DVD burning?

[Ian]

They're slowly catching up. Most of the newer drives can rewrite at 16x or 24x.

[flash]

They probably have to use up their stock pile of old tech
sitting on their shelves.

[bob11879]

The optical pickup has to incorporate two laser units and the drive has to be able to write to the smaller pitch of DVD and the larger pitch of CD-R. Not all drives can track correctly at higher speeds with this combo pickup. The Plextor 708A will write and read at 40x and RW at 24x.

[Boone]

DVD discs are much denser than CD, so lower motor speeds are required for even 8x burning. To use a motor that is deadly accurate at case-rattling speeds is VERY expensive.

[hoxlund]

my new Plextor 708a has 40x cd-r write speed, 24x cd-rw write speed