steven c wrote:

> Question for the technically knowledgeable...
> Since CD's and DVD's are (AFAIK) more or less the "same animal" and
> operate by pressing (or "burning") pits into the surface of a plastic
> disc, why should there be any difference in the lifespan of the two?
> Do the littler "holes" fill themselves up more rapidly?

The materials are different, though similar. In particular, the dyes 
proved for recordable CDs are not usable for DVD.

The data density is higher on DVD than on CD. As a result, apart from 
ECC it takes less damage to lose information from a DVD than from a CD.

I believer there are also additional failure modes for DVD, notably 
those associated with dual layers.

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