How long does data last on a DVD or CD

This is a question I was asked today –

“I read and hear from time to time that recorded CD’s only have five possible more years longevity. I’m not sure whether this just applies to CD-R type discs , hopefully original CDs last longer than this. What about yours?
I appreciate much depends on how stored but wondered what your take is on this subject?”

My Reply:
“This is a difficult one and I’m afraid I don’t have a definitive answer. There are so many conflicting reports about this – I guess we’ll never really know until the problem is upon us, which is no help at all!

I have CDR’s with music and back ups on going back 10 years or so which I have no problem with, and most reports seem to show that 50 years is easily possible but not guaranteed.

I don’t think the main problem with CDR’s is that the data ‘disappears/degrades,’ the concern appears to be with how CDs are manufactured. It seems that CD’s can de-laminate starting at the outside edge due to poor adhesives. I would assume the better the quality the disc the more chance you have of avoiding this – hopefully! The good thing is, is that data is written and played from the inside to the outside on a CD so all or most of your data should stay intact, assuming the CD is still playable if it’s fraying at the edges that is!

In the next few years CD’s will be ‘a thing of the past’ and we’ll be onto the next generation of data storage – mainly on hard drives in ‘the cloud’ I suspect. Many laptops are being shipped now without CD drives – a similar story to the fate of the old floppy disc.

Apple already offer iTunes Match which allows mass storage of your iTunes purchases and also any CDs you have imported which is a pretty good. Of course the music is compressed unfortunately but at least Apple use ‘AAC’ encoding which is better than MP3 in my opinion.
If it’s any consolation I always use high quality grade A discs, burn them at a slow speed for accuracy and store them sensibly – I’m not sure anyone can do much more than this.

It’s an interesting dilemma!”