cstr20cstr

Hi, this is a rather serious topic about disk lifetimes.

Does anyone know of a reliable source that truthfully explains CD lifetimes, and comparison of say CD, DVD, and HD DVD lifetimes.

I've heard all kinds of numbers thrown out in magazine articles, web articles, and the only thing in common is they all don't seem to really know for sure.

I have a music CD I bought in 1985, that still runs PERFECTLY, yet I have a game CD I purchased 1 year ago that is corrupt already. Both have no scratchs or physical damage.

What's the physics behind all this and disk deterioration. Obviously a disk stored in near a swamp is going to die sooner, but then you can store disks in good dry climates and some will last many years while others won't. And what about disk data density ? Is it safe to assume as disks become denser (like the new HD DVD's) they'll have shorter lifetimes ?

Fox

I've checked up on this before, and almost all of the sources I've seen have pinned the lifetime of CD-Rs at around 10 years, with a ton of variation depending mostly on the wear and tear, environment, and an often overlooked factor- the type of dye used in the disk. Cheap disks often use trash dye, so it deteriorates faster.

Also, from my experience, audio CDs are far less prone to not working at all than CD-roms. My brother has a Blink 182 CD he burned maybe 8 years ago. It has scratched on the dye (label) side of the disk, and even missing pieces of that technicolor foil we all know and love. He painted over those holes with white-out, and the CD still plays, god knows why. I think this is simply because a CD player can sort of extrude the general idea of the sound even if there's a little bit missing, but a computer can't execute code that isn't there or guess what used to be there.

The factors that I've heard play into the deterioration are not so much humidity, but light exposure and temperature. NIST would disagree, but I don't think it makes a difference unless there's a rapid humitidy change, or if you're submerging them.

From my experiences, it seems as if commercially manufactured CDs and DVDs will far outlast copies made on a computer. Believe it or not, those disks are created from a "master" disk, made of glass, and then copied by stamping (or injection molding) the image of pits created from that master into the copies.

For more info, just go to a search engine and type in "CD longevity". That's how I found out most of what I know about this.

TheMatt

It also seems to depend on the player and how "picky" it is. My laptop will read virtually any DVD that I throw at it, even some scratched up DVDs that I've had a couple of years that I didn't take care of as well as I should of. But if I put those DVDs into a standalone DVD thats in my bedroom, It will reject the DVD's even some new ones that are only a couple of months old.