In the Interesting & Peculiar Products section of the new Cites & Insights, discussing the prospects for 500GB optical discs, I question an assertion that the real-world lifespan of optical media is “well under ten years” and note that “I have 25-year-old CDs that work perfectly.”
A reader says that her eight-year-old CD-Rs are unreadable and questions what I’m saying…and says industry estimates are about ten years.
So here’s a clarification:
- The paragraph I was questioning specifically said “mass-market physical medium”–by which I assumed pressed/pre-recorded media, not recordable media.
- My context was 25-year-old audio CDs (pressed audio CDs)–and every one of the (prerecorded) CDs I purchased two decades ago still works perfectly.
- While there are special archival optical media, I can’t speak to life estimates for recordable media–although I do have (audio) CD-Rs that are still readable after eight years, that’s anecdata.
- I would also note that the paragraph I questioned said people wanting long-term archiving would stick with magtape. Permanence of magtape ain’t so hot either…
Meanwhile: I am not an expert on archival media (and other than ink or properly-fused toner on acid-free paper and *maybe* high-quality microfilm, I don’t know of any), and my casual comment should under no circumstances be assumed to be a guarantee that the DVD-R you burn today will be readable in 25 years.
