More on optical disc longevity (posted 2024-05-09)
Two years ago, I wrote a blog post on the longevity of optical media. Today, I found out that the Canadian government also has an interest in this topic and produced the following article: Longevity of Recordable CDs, DVDs and Blu-rays.
Much recommended if you're interested in the topic. However...
Although I'm sure their findings that a gold reflective layer is much, much better than silver / silver alloy / aluminium, I find their conclusions for "regular" CD-Rs, CD-RWs, DVD-RWs and DVD+RWs, based on accelerated aging tests, clash with my own experiences.
CD-RWs are rated for 20 to 50 years, but in my experience, those are not reliable at all, with most of them failing in well under 20 years. Rewritable DVDs are even worse, regularly failing immediately.
Mass manufactured read-only DVDs and BRs are listed as 10 - 20 years. I can't think of any of the about 200 that I have that fall in that age range failing to play because the disc was unreadable.
BD-REs (rewritable blu-ray discs) are listed as 10 - 20 years, which is not too bad, but BD-Rs only 5 - 10 years. I'm glad to report that my oldest ones, both two years old, still read without trouble, but this seems a very low number... especially for HTL discs that don't use organic dyes. Can it be right?
Also see this on M-DISC longevity.