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Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

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Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#31

Post by ricardobeat »

masklinn wrote: post #28
ricardobeat wrote: post #25

That longevity table is under archival conditions (climate controlled). The vast majority of CD-Rs I had, regardless of brand, were completely gone after 10 years of storage in an enclosed textile bag. CD-RW would barely last 2-3 years.

Brand / media quality also matters a lot. I had some cheapo bulk CD-R whose top (reflective) layer started flaking after a few years (stored in their sleeves in a cardboard box in a dry cabinet). Stuff from reputable brands still look great, but I haven’t hard had a CD or DVD player in years if not decades at this point so it might be a cesspool of data loss for all I know.

I used to buy those thick white labelled discs in a spindle, with a green reflective layer, and remember them being quite a bit more expensive. Can’t say I I’ve ever noticed a difference.

The ones that are still playable (I hope so? Last checked maybe 5 years ago) are all industrial pressings.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#32

Post by Test0129 »

After quite a bit of research into this about a year back I decided to archive everything on archive-grade CD-Rs. 20-50 years is more than enough and realistically in the correct climate (a safe or something that humidity would have trouble getting into along with dessicants, etc) could last much longer. I evaluated magnetic tape, HDDs, and a few other options are CD-Rs are as good as magnetic tape (in longevity) and will likely have readers well into the next century.

But you have to be very careful. There are a few brands, in particular Taiyo Yuden that are the absolute best. CMC Pro is a related brand with the same technology/longevity (and easier to get). You will pay quadruple the cost per CD but its worth every penny.

Avoid Memorex, JVC, etc. Basically any brand you can pick up at your local big box retailer.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#33

Post by naikrovek »

OptionX wrote: post #20

What would one use as a media for long-long-term storage, taking only into account the resisiliance of the ability to read the data from it? For example if you wanted to store data in a time capsule for like 100 or 200 and you where ganrateed the people on the other side had a reader capable of reading whatever media, and whatever format you chose.

there is no "archive and forget" method.

the library of congress uses contemporary storage media (hard drives), and migrates everything to newer storage media as the previous media becomes obsolete and replacement hardware for that media stops being manufactured.

they have learned that stockpiling old reading hardware and software isn't sufficient to be able to read that media in the future.

they move everything to new media manually and archivists and volunteers work continuously to bring data on hardware more than one generation old into the current generation as everything progresses.

source: I read it in a detailed article about the LoC a couple of years ago and have forgotten where. :(

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#34

Post by TedDoesntTalk »

Test0129 wrote: post #32

After quite a bit of research into this about a year back I decided to archive everything on archive-grade CD-Rs. 20-50 years is more than enough and realistically in the correct climate (a safe or something that humidity would have trouble getting into along with dessicants, etc) could last much longer. I evaluated magnetic tape, HDDs, and a few other options are CD-Rs are as good as magnetic tape (in longevity) and…

> Taiyo Yuden

I have not been able to buy these in the last few years. Also, when I was able to buy them, one had to be careful of counterfeits.

Do you have a source for them?

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#36

Post by sammalloy »

All of the CDs in my old collection are fine, but I’ve had major problems with my DVD collection. I haven’t spent any time trying to figure it out, but it looks like some kind of unusual mold that I’ve never seen or some kind of deterioration of the substrate occurred inside some of the discs and they became completely unplayable. Attempts at cleaning completely failed to solve the problem. Is there really a major difference between DVD and CD manufacturing on a commercial level?

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#37

Post by masklinn »

OptionX wrote: post #20

What would one use as a media for long-long-term storage, taking only into account the resisiliance of the ability to read the data from it? For example if you wanted to store data in a time capsule for like 100 or 200 and you where ganrateed the people on the other side had a reader capable of reading whatever media, and whatever format you chose.

Paper is a good one but the media is low-density and fragile. Although pre-industrial forms of paper (e.g. cotton paper, or papyrus) might have more long-term resistance than modern wood paper.

Fired clay tablets are much more resistant, but lower density (because clay), unless you use a dedicated press maybe (most of the ancient Near East clay tablets were actually fired fortuitously e.g. by a building burning down, that was only rarely intended and most tablets were used as erase-boards). But obviously non-tablet pottery can go through millennia in rather good conditions.

Carved wood is also a good idea, but it still needs good conditions and maintenance. Still, in the right storage it can last for centuries (see the Tripitaka Koreana for instance).

Leather, parchment, and vellum too, but I think then your main concern will be the degradation of the pigments.

If your focus is on longevity above all else, then you can’t beat stone. Though that can still be destroyed. I guess above stone would be highly non-reactive metals, however you’d need a metal which is not very precious as well (e.g. not gold, or silver, or platinum). I’m not very versed into metals and metallurgy, but I’d look towards titanium (it’s extremely reactive but not at normal temperatures), or bronze.

At one point there were disks made out of glass (versus the conventional polycarbonate), in theory that gives them infinite lifetime short of being physically destroyed. Though it does assume a compatible drive device.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#38

Post by xerox13ster »

darkwater wrote: post #29

Totally anecdotal but just a month ago I opened a box from my last moving (ended 4 years ago...) and I found a CD-RW labeled "Backup 2001", which survived 5-6 relocations, even an international one. Well, I put it into an USB DVD player I have aaaand, it starts spinning and spinning and spinning, and nothing shows up in Nautilus. Looking at dmesg I see a few I/O errors on the device. Then, I try ddrescue [1], start e…

IIRC there was an import/conversion tool in Outlook 2003/2007.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#39

Post by TedDoesntTalk »

mrfinn wrote: post #22
kevin_thibedeau wrote: post #11

Earlier quoted context omitted.

For DVD (and the rare M-DISC CDR) yes. For BluRay there is nothing special about them.

Any references about the BluRay claim? Genuinely curious

Where can you get MDISC CDR?

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#40

Post by em500 »

kevin_thibedeau wrote: post #11
karencarits wrote: post #7

Earlier quoted context omitted.

Do we actually know that M-DISCs are much better than ordinary discs regarding longevity? I wasn't really convinced by the wikipedia page

For DVD (and the rare M-DISC CDR) yes. For BluRay there is nothing special about them.

It's a bit more nuanced than that. Standard CD-R and DVD-R uses organic dyes for the recording layer, which are sensitive to light and humidity. M-DISC DVD-R used some proprietary inorganic layer, which was more durable in theory and in independent lab tests[1].

When BD-R was introduced, all discs used the same inorganic recording layer, including M-DISC BD-R. That, plus the lack of independent tests, plus the fact that the manufacturer Verbatim likes to muddy the waters between M-DISC DVD-R and BD-R, led some people to conclude that there is nothing special about M-DISC BD-R. However, after a few years, disc manufacturers started making BD-Rs using organic recording layers again with inferior durability[2]. Initially these were marked as "LTH" discs (with the original non-organic BD-Rs marked as "HTL"), but nowadays they mostly stopped marking them at all so you simply don't know what you buy.

With M-DISC BD-R you'll likely get a HTL disc (but it's not garanteed, since they don't advertise it either). Additionally, there's more to durability than the recording layer (such as the material of the reflexive layer, and the overall build quality). And there is at least some anecdotal evidence that M-DISC BD-R are indeed more durable than the median BD-R[3,4].

The consensus among enthusiasts is that for BD-R, M-DISC and Panasonic HTL (Made in Japan) are very good. But they come with a big price premium (about $2 per disc vs $0.60 for some generic LTH disc).

[1] https://en.wikipedia.org/wiki/M-DISC#Durability_claims

[2] https://en.wikipedia.org/wiki/Blu-ray_Disc_recordable#Record...

[3] https://blog.ligos.net/2022-04-02/The-Reliability-Of-Optical...

[4] https://www.microscopy-uk.org.uk/mag/artsep16/mol-mdisc-revi...

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