short lifespan of CD-R's?

[smeggy]

Very odd, I have a large number of disks that go back to 1996, various brands, various burners and they all read fine. I can't recall the last time a cd-r failed on me. Significantly longer than 2-5 years in my experience.

 

[NotJeffBuckley]

Quote:

Originally Posted by smeggy Very odd, I have a large number of disks that go back to 1996, various brands, various burners and they all read fine. I can't recall the last time a cd-r failed on me. Significantly longer than 2-5 years in my experience.

Well, theoretical instability is of course spotty in real-world scenarios, especially among well taken care of CD-Rs. It's entirely possible for it to last our portion of forever, just very, very, very unlikely, if you catch my drift.

 

[smeggy]

I suppose it could be that older disks were of higher quality than newer ones and thus last longer than their newer counterparts. I don't know if my current batch will last as long

Have to wait and see. I prefer to multi-archive on HDD these days anyway now it's so cheap and a lot faster.

 

[NotJeffBuckley]

Quote:

Originally Posted by smeggy I suppose it could be that older disks were of higher quality than newer ones and thus last longer than their newer counterparts. I don't know if my current batch will last as long Have to wait and see. I prefer to multi-archive on HDD these days anyway now it's so cheap and a lot faster.

I assume you took good care of them?

I'm not entirely sure which way to lean on "the early ones were better."

Two scenarios propose themselves:

1. The processes and methods in use were not fully understood, so products were overengineered in order to exceed minimum specifications so that there wouldn't be any hiccups with an early technology, limiting its market penetration and putting people out of business. As time went on and the science of CD-R making evolved, manufacturers began cutting costs where possible and using less expensive dyes, etc., in order to maximize profit.

2. The processes and methods in use have been refined over time so that CD-Rs made today are catagorically of a higher quality than the similarly-tiered ones made at the onset of the medium.


Could be that neither one's at all accurate, but speculation is fun

 

[halcyon]

1. I'm afraid that ID codes (ATIP, ADIP) can be faked. There are both faked stampers and cross-licensing that makes the situation complicated. Not all media is what it claims to be (via it's ATIP code), and as results can be of really bad quality (there are hundreds of readability scans in a forum like cdfreaks.com that show this unfortunate situation).

2. Which disc is guaranteed? Don't trust the manufacturer ratings! If a manufacturer claims a 100 year longevity, it may mean nothing. A case in example: Verbatim DVD media rated for dye longevity of several decades, consistently fails in the hot & humid day-to-day home climate of Singapore. In less than a year! If you want to be safe, gold/phthalo CD-R discs are the only ones that are known to be safe for long. For other disc types, we just don't have enough of information.

3. Claim: "Longevity of media for consumers is irrelevant" is wrong, imho. This claim only holds value, if you store useless crap, mostly illegal bad quality copies. If you have personal digital creations, photos, digital videos, etc. which are unique copies of some experience, then they might have very high personal value to you.

4. Silver vs. Gold for compatibility vs storage Cyanine and azo are more compatible for burning. Silver has higher reflectivity and offers higher compatibility for reading. HOWEVER, all of those offer WORSE longevity for storage than phthalocyanine on gold. Pick your poison. If you know you can burn good quality burns with phthalo/gold discs, then they are the best option for long-term stable storage.

5. Old CD-R discs were better than today's. This is a complicated subject and cannot be summarized into one sentence. In many ways the QA, materials and the processes of CD-R from the golden period (c. 1995-2000) were better. They cost more to produce, they were produced slower, with higher QA, with more expensive materials. However, they didn't have all the advantages of what the best media today can have (better UV shields, better scratch resistant materials esp. on label side). Today most of the CD-R stuff is produced in countries where it's the cheapest to produce, with extremely low manufacturing cost (cheapest machinery, cheapest QA, cheapest materials). This has clearly taken a toll on the quality, even though the advances in the best-of-breed machinery/materials/processes have gone forwards since those times. It's just that very few if any use these best-of-breed methods, because it's too expensive and we want to buy the cheapest stuff there is!

6. Claim: "my discs from 199x read fine, this is all paranoia" is not the whole picture. Again, quality of discs from c. mid nineties was on the average better. Also, just because many of us have stuff that has lasted more than a decade, doesn't mean everything will. Case in point: go to cdrlabs or cdfreaks and look for threads on failed cd-rs. You'll find cases where discs have failed in less than a year. I once tried to recover stuff off a friend's 8 month old dics that looked to be in pristine condition, except that pinpoint holes had formed in the reflective layer. c. 60% of the data was completely unretrievable by conventional methods. The cheapest possible aluminium type refletive layer had completely oxidized (due to bad sputtering and consequent exposure of the reflective layer). I've even had the best of Kodak's Ultima Guard Gold peel on me physically from the label side. And these were are a time the best discs you could buy. It's all about quality of the disc, quality of the burn, method of archival and environmental factors. It used to be long ago that all Fujifilm CD-Rs woulf be wiped completely blank if they were exposed to two weeks of direct sunlight (UV radiation killed them).

In summary, I'm not trying to be an alarmist. Your data may be safe, it may not be safe. It all depends. There are way too many factors to give just simple answers without knowing the specifics.

HOWEVER, if you are dealing with unique data of value (personal, financial or otherwise) and you are storing it on optical media, then you need to take notice.

If cd-rs are just a throwaway type temporary convenience type storage form, then don't fret about it.

It all depends on what you need, how long you'd like your data to stay intact, can you replace it if it's gone (with how much work) and how much you are willing to invest in keeping it safe.

With that in mind, I conclude this long 'summary'

I'll post more detailed recommendations as I come across reliable data on the issue.

best regards,
halcyon

 

[NotJeffBuckley]

Quote:

Originally Posted by halcyon 5. Old CD-R discs were better than today's. This is a complicated subject and cannot be summarized into one sentence. In many ways the QA, materials and the processes of CD-R from the golden period (c. 1995-2000) were better. They cost more to produce, they were produced slower, with higher QA, with more expensive materials. However, they didn't have all the advantages of what the best media today can have (better UV shields, better scratch resistant materials esp. on label side). Today most of the CD-R stuff is produced in countries where it's the cheapest to produce, with extremely low manufacturing cost (cheapest machinery, cheapest QA, cheapest materials). This has clearly taken a toll on the quality, even though the advances in the best-of-breed machinery/materials/processes have gone forwards since those times. It's just that very few if any use these best-of-breed methods, because it's too expensive and we want to buy the cheapest stuff there is! best regards, halcyon

So was I right with scenario 1, then?

 

[smeggy]

My oldest disks are all 'Gold'. They are all stored in a room with low light levels, stable humidity, even temperature etc. so I guess they are reasonably looked after. Important stuff is also backed up elsewhere so if they do eventually rot I won't be too concerned.

Now if you really want short lifespan, I have a nice pile of 3.5" floppy disks I can sell you

 

[halcyon]

Quote:

Originally Posted by NotJeffBuckley So was I right with scenario 1, then?

I think so and the overall anecdotal data I have available suggests this as well.

Also, I think it's an overall tendency in manufacturing... cheaper, faster, shorter lifespan. Lower costs, better profits, more renewal purchaces, more throwaway culture. All good for the business

 

[Anders]

Another concern if the CD you buy really is a pressed CD or a CD-R. I don't know how common it is that what you get is a CD-R. There has been fake Mofi CDs sold at German Ebay that seems to be CD-Rs, at rather high prices. Maybe small bands also release their albums as CD-Rs, that should be cheaper when a small number of copies are produced. I also think this applies to some bootlegs.

 

[markl]

To those who report no problems with very old CD-Rs-- I would be curious to know if people notice a difference between the *playability* of an old CD-R on a CD player, vs. how easy/hard it is to get a good extraction of data from that CD-R using a demanding program like Exact Audio Copy. I expect the older discs may still play fine, but try extracting that data to burn a new one and see if it increases the likelihood that EAC chokes on it with read and sync errors.

 

[Anders]

It would be hard to say if a CD-R that plays without problems has deteriorated or not based upon some measurement of read errors, as from EAC or the Plextools measurement (that requires a Plextor burner). The variation in read errors is huge among newly burned CD-Rs depending on burner, speed and quality of media. Even if there are unrecoverable read errors in the CD-R, it is difficult to say if this depends on aging of the media, a CD-R that was defective from the beginning or a possible incompability between the burner and reading player.

I can't see any other possibility than making a measurement after the CD is burned and reapeat it after some years. Maybe you could get a reasonable estmate of the typical error rate from old tests at the sites halcyon mentioned above, if you know the original burner, speed and media and find comparable data for newly burned CD-Rs.

There are usually many thousands of recoverable read erorrs on a CD-R.

 

[replytoken]

"4. Silver vs. Gold for compatibility vs storage Cyanine and azo are more compatible for burning. Silver has higher reflectivity and offers higher compatibility for reading. HOWEVER, all of those offer WORSE longevity for storage than phthalocyanine on gold. Pick your poison. If you know you can burn good quality burns with phthalo/gold discs, then they are the best option for long-term stable storage."

I thought that MAM's Silver discs did use phthalocyanine? Is my assumption incorrect?

 

[halcyon]

Quote:

Originally Posted by markl To those who report no problems with very old CD-Rs-- I would be curious to know if people notice a difference between the *playability* of an old CD-R on a CD player, vs. how easy/hard it is to get a good extraction of data from that CD-R using a demanding program like Exact Audio Copy.

I scanned mine with Plextor and LiteOn cd-drives for C1/C2 data and analyzed the results. There are tools for this (CD-DVD Speed, kProbe, Plextools Pro).

The data was also readable with the dvd-rom drives I had (some of those can be really picky with older cd media, even some pressed audio cds can turn up as blank sometimes).

Also, as Anders noted, there are always C1 errors on all cd discs, so one has to know what to look for (what amount of each ECC level errors and from which reader).

Also, dvd-burners are notoriously non-representative of the general drive population for reading back C1/C2 data from cd discs and can underreport drastically.

regards,
halcyon

 

[Eagle_Driver]

Quote:

Originally Posted by replytoken "4. Silver vs. Gold for compatibility vs storage Cyanine and azo are more compatible for burning. Silver has higher reflectivity and offers higher compatibility for reading. HOWEVER, all of those offer WORSE longevity for storage than phthalocyanine on gold. Pick your poison. If you know you can burn good quality burns with phthalo/gold discs, then they are the best option for long-term stable storage." I thought that MAM's Silver discs did use phthalocyanine? Is my assumption incorrect?

To be specific, phthalo/silver discs offer significantly poorer resistance to UV and humidity than do phthalo/gold discs.

 

[RogerWilco]

I read somewhere on the net where the riaa has no control over people coping analog.So what they were going to propose was Technology that erases a burned disk after it is played for the first time.If something like this were to be passed somewhere in the furure that would make all burned cd's obsolete?