I have read a bit about DVD-Rs and CD-Rs construction and I wonder if the DVD will last much longer by its physical construction. One thing for sure is that when you scratch a CD-R labels surface, you can get all data lost if the recording layer peels off. I have tested with a knife, scratching a DVD-R and the label surface is very resistant even against needle hits. That is because the recording layer resides inbetween plastic platters whereas the CD-R label does not have that kind of protection. This alone will ensure a much longer life by not letting the dye component/reflection layer peel off.

As for the dye of a CD-R and DVD-R, are they basically the same thing that degrades over time? The other day I picked up a genuine Sony CD-R recorded in 2003, that was safely kept and played once or twice. The disc edge was yellow-ish and the label layer was starting to peel off from outside in, even without any use. Does this happens with DVD-Rs too? Although DVD-Rs are more resistant against peeling off, could they at some point become unreadable because of the dye internal corrosion?

This shouldn't be happening to properly stored CDs.

cdfreaks is a very good site for this. They have a thread for testing ageing media of all types.

Taiyo Yuden and Verbatim are usually the best quality I have found.

Don't forget to use dvdisaster (just in case).

Etropy always wins. The only variable is how long.

IMHO, spirituality trumps entropy, as time is just another form of lower matter.

I was unable to find any testing on cdfreaks on the effects of praying for CD-Rs.



EDIT: s/of/on/

I have a bunch of CD-R (about 300 or so) that have been filled with computer data, burned as far back as 1996. The brand names vary from Memorex, to Verbatim, to Phillips, to TDK, to generic.

They contain data such as ZIP files, JPEG images, MP3s, and even MIDI/MOD/XM files. Each CD-R is pretty much full too, containing ~640MB of data (I have this slight tick about not burning a full CD/DVD). They were burned at about 4x.

I tested a dozen of these discs so far, readable just fine. The ZIP files open fine and fully extract. The JPEGs are fully viewable. And the MIDI/MOD/XM files fully playable.

The key is storage method, as I've kept each CD-R securely in it's jewel case, in a nice, dry place, room temperature.

I have several thousand DVD-R/+R that I've burned, various brands, as far back as 2004. So far, doing a sample of a few dozen, they are all readable. They are stored in the same room as the CD-R above, so same environmental conditions. I'll see in another few years if they are still readable.

It is not necessary to listen to every XM file to determine if it's ok. That's the beauty of a proper computer format with error detection and reporting.

But if you discover unreadable files it is already too late. And a single read error does not really tell much about the character of damage to your disc. It could be a scratch, a hole or, if the errors are distributed across the entire area or near the edge, media deterioration over time. Disc quality scanning will reveal the frequency of errors over the whole media length.

I have recorded a TYG02 (False?) Egital DVD-R media in 2004 and I have kept it like crap, the surface is fully scratched (low level scratch) and it has fingerprints and dust. I ran a test using DVDisaster and I was impressed, not only the disc was read much faster than others (Sony/Sony, Maxell/Ritek, Philips/CMC) but it was fully stable and didn't have a single damaged sector.

I have bad experiences with media. Although CDRs are longer on the market, so I can't say what will happen with my DVDs, but my experience is this:
Quality media in '94-'99, when I started getting games from my local pirate were old golden Traxdata, and later there were some BASF - Traxdatas were really golden colour, not todays greenish ones, BASF were dark blue. I still have some of these media, I have my old Amiga games backups on them, and they are still readable - but the read curve isn't perfect. There is a lot of spining up-slowing down when reading these... of course, these are backuped on tapes and these media were expensive back then.
Later, CDR became cheaper, and I was cheap then so I bought cheaper media - produced by Princo, Moser Baer, Traxdata, Acer... and until now almost all of them failed. Read this as 85 of 100 is in garbage. They were great when burned and for the first year - but then they showed quite a bit of CRC errors. Then I started testing media, reading about it, and since 2002 I am using only TY and MCC media. From time to time I go on with experimenting and a year back I bought TDK DVD+R media, which is really TDK, and not some other factory... and they still last.
About DVDR, the same applies here - I was using Arita, Princo, Traxdata, Acer.... all of them coming from different factories, but same thing happened to them, with a few exceptions. From a bunch of Arita's, only one survived. I have quite a few older Princo media still alive - newer didn't last long. Traxdata media is mixed - older ones (8x) are still OK, newer are already dead. In the last 4 years I buy strictly TY and MCC DVDs, with TDK exception.
And that software pirate quit pirating job long time ago, gave me his C64 collection of tapes and Amiga CDs, sold out all of his pirated software, and started working in one hardware distribution company

I have a Dysan CD-R from the time when The Elder Scrolls:Daggerfall came out (summer/autumn '96). And it still reads well and doesn't show any signs of errors (drive reducing speed etc.).
The pirated copy did cost almost half the original game back then. (Now, it is considered abandonware and may be downloaded for free)