why are cd-r discs still only available mainly up to 700mb?

[tali122]

why are cd-r discs still only available mainly up to 700mb- whats the problem with creating 1gb cd-rs , 700mb discs have been available for ages , i thought technology would have moved on , but in this case apears to have stagnated

[stevie21]

When CDs were designed, they were designed to hold one particular classical concert of a certain length.
Without changing the design, how the data is stored, how devices write the info to them and read from them it's probably not possible to create a 1GB CDR.

If any one of these was changed for a future CDR it'd only be compatible with newly invented CD drives/hifis etc.

If space is that much of an issue I'd recommend getting a DVD writer - I got mine for just under �50.

[fo3nix]

technology has moved on, and they call it DVD. it's since moved on again, to various forms of HD-DVD, such as blu-ray.

[jock]

With reference to the capacity of CDs, it's true they have
"topped out" at 700mb, but the speeds at wich you can write to them has increased significantly, as well as the protective dyes and coatings which have improved longlevity and accuracy of writing. fo3nix is right the natural successor of CD is DVD, then either (or both) Blu-ray or HD DVD, whichever wins the format war!

[Mobius1]

Most CD-R/RW designs have topped out at 700MB, but some mnufacturers, such as TDK have created high-capacity 800MB CD-Rs that are compatible with standard CD-R burners.

The problem with trying to fit more data onto the same size disc isn't down to disc technology, but rather the laser technology used in CD-R/W drives. It emits a class 1 laser at a certain wavelength, which means the pits on the disc can be spaced (when recording) a certain distance apart (usually measured in fractions of nanometres). Newer technology like DVD, Blu-Ray, HD-DVD and Ultra-Violet Discs use different types of lasers that either have a slighty shorter wavelength (DVD) or significantly shorter wavelengths (Blu-Ray, Ultra-Violet).

This means that they can pack significantly more pits onto a single disc when recording, and have the even-more-than-pinpoint-accuracy required to detect millions of those pits every second when reading those kinds of discs. So, in fact, massive strides have been made in this aspect of technology, but there's only a certain amount you can do with the CD-R/W type lasers.

[twiglet4frog]

the advent of dvd recorders and now HD dvds are what put paid to further techno research on cds