what prevents DVD-R drives from having faster CD-R speeds?

[Lucky]

what is the technical limitation? they are only like 12-16x max right now.

 

[KenGr]

I think it's a matter of optimizing them for DVD writing. I haven't gone through the math but I would guess the data rate for 2X and 4X DVD writing is similar to the 16X CD writing. I'm sure that, at higher cost, you could add separate circuitry to get very high CD-R speed but would that be a selling point? Probably not. Most of us using DVD-R are much more interested in getting to 8X DVD writing than faster CD writing.

 

[Lucky]

right, i understand that. very few people are clamoring for this, so is it a marketing decision, or would two lasers be required? I'm clueless about this, so any helpful answers would be appreciated.

 

[AluminumStudios]

DVD technology for the most part is identical to CD technology with one major difference - it uses a finer laser to get higher data densities. I think (don't quote me on this) that CD-R's use a laser with a 720 nanometer wavelength (into the infrared spectrum) and DVDs use like 680 nanometers (into the red spectrum.)

Of course with a finer laser more precision is required of the mechanism as a whole. Manufacturers like with all technology build it the best they can at first then keep refining it as they discover bugs and new methods for improving it. That makes the speeds go up ... just like with CPUs or the path that CD-Rs followed years ago.

Also, if I"m not mistaken 1X in DVD terms is like 8 or 10 megabits (which is 1,000 - 1,200 KB/sec) while 1x in CD-ROM terms is 150 KB/sec (these are based on the minimal speed needed to play DVD video discs and audio CDs respectively.)

 

[Lucky]

up for more answers 🙂