Say Goodbye To Your CD-Rs In Two Years? 707
Little Hamster writes "According to an article on cdfreaks.com, a test done by the Dutch PC-Active magazine showed that among 30 different CD-R brands tested, a lot of them were already unreadable after twenty months. This is shocking, and makes me wonder how should I backup my data, photo and music collection."
simple (Score:3, Informative)
Keep upgrading your Harddisk from time to time and backup data from old HD to new one.
Happened to me (Score:2, Informative)
To make them last longer... (Score:2, Informative)
treat them like a mushroom and keep them in the dark.
I have many CD-R discs that are still quite readable despite being 4-5 years old. On the other hand, I've seen a disk erase itself in less than a day when left in direct sunlight, and many disks will slowly degrade at light levels found in most human-occupied spaces.
Re:To make them last longer... (Score:5, Informative)
RTFA. That's what they did; they kept them in a closed cabinet for two years in their original packaging. Some brands were toast after two years.
The fact that your CD-R discs appear to be readable after 4-5 years isn't a useful data point. These guys used CD analyzer hardware (CDA-3000) to check the quality of the discs. CD's have error checking and the damage may not yet be noticeable to the end user until later.
Re:Blah, physical backups (Score:2, Informative)
http://www.csua.berkeley.edu/~emin/source_code/
But remember, sometimes you don't miss the things that were lost after a crash... if you don't, then you are a happy person!
Karma Whoring (Score:2, Informative)
CD-Recordable discs unreadable in less than two years
Posted by Dennis on 19 August 2003 - 14:33 - Source: PC-Active
The Dutch PC-Active magazine has done an extensive CD-R quality test. For the test the magazine has taken a look at the readability of discs, thirty different CD-R brands, that were recorded twenty months ago. The results were quite shocking as a lot of the discs simply couldn't be read anymore:
Roughly translated from Dutch:
The tests showed that a number of CD-Rs had become completely unreadable while others could only be read back partially. Data that was recorded 20 months ago had become unreadable. These included discs of well known and lesser known manufacturers.
It is presumed that CD-Rs are good for at least 10 years. Some manufacturers even claim that their CD-Rs will last up to a century. From our tests it's concluded however that there is a lot of junk on the market. We came across CD-Rs that should never have been released to the market. It's completely unacceptable that CD-Rs become unusable in less than two years.
On the image you can see the exact same CD-R. On the left you see the outcome of our tests done in 2001. On the right you see the same CD-R in 2003. The colours indicate the severeness of the errors in the following order; white, green, yellow and red whereas white indicates that the disc can be read well and red indicates that it cannot be read.
For those of you who are interested, the original Dutch article can be found here and in the September issue of PC-Active. Please discuss this subject in our Media Forum.
Re:More of the article should be translated. (Score:2, Informative)
You get what you pay for. (Score:5, Informative)
FWIW, I can't remember having a single CD-R go bad. I've had some scrathed ones which took a while to read because the reading drive slowed to a crawl, but I got the data nonetheless. I even recently found what must have been one of the first CD-Rs I've ever burned. Must have been from around '96 or '97, it had my backup copy of Duke Nukem 3D on it, among other stuff, and everything read fine (the disc was a Sony CDQ-74CN).
Re:but something is missing... (Score:5, Informative)
Re:More of the article should be translated. (Score:3, Informative)
The part they translated from the online article is pretty much all the substance there is in it. The actual results and further information aren't there.
The last paragraph of that:
In the September issue of PC Active, that will be in stores on 22 August, the shocking results are described in detail. Besides the possible causes of losing data over time we also a give a number of valuable tips to preserve the data on a writeable CD for the future. On the free cd-rom there is also a program to discover the state of a cd-rom for yourself.
So the info is in the paper version, and I don't have it.
Not surprising, and not new (Score:5, Informative)
The first thing to understand is that WORM systems, true WORM systems, not the Magnetic-Optical pseudo-WORM systems, are built on ablation of material in the disc itself. In other words, you burn holes in the disc revealing a lower layer that is reflective. In the case of most discs, and Kodak especially, they were gold on the reflective layer for long-term stability. Various tests of accelerated degradation were performed in both climate stabilized and non-stabilized situations, and at worst, the discs were stable for 100 years before any error correction was necessary.
We decided to perform the same kind of evaluation of CD-Rs, and found that brand varied greatly. The best were stable for 3-4 years, the worst only 6-8 months if the climate changed dramatically. In addition, UV exposure had a radical impact on the life-span of the disc. Further research found out that the problem was the natural instability of the organic dyes that were used in the disc layers.
Basically, if the disc wasn't perfectly sealed (look at the work done in the referenced article, and how it starts at the edges), oxygen would get in and react with the dye, which would change it's characteristics relatively quickly. It doesn't take much before the dye structure collapses, and data becomes unreadable after a short period. While I suspect the dyes have gotten better over time, they're still organic last I knew, and still subject to degradation by contact with air. Quality control is the only thing that will get you anything here, and I suspect even the best dye-based discs can't make it past 20 years unless exposure to UV is totally eliminated.
What Kodak had developed was what they called "Century Discs", which were basically scaled down WORM discs, but in CD-ROM format. They were gold inside, non-reactive, and well made. They did, however, require a very expensive writer because they needed more power than a CD-R drive could ever hope to provide to force the burn away the spots. They were, however, readable in a normal drive.
That's just my experience, but everytime I've seen an organization talking about "archiving" on CD-R, I have issues with it. It's fine for "backup," where the data cycle is shorter, but true archival purposes (for example, financial data), it won't cut it. You either need to use WORM, or tape. Tape is, however, subject to problems over the cycles as well, witness the failing properties of 9-track tapes written by NASA in the 1970s (heard first hand, not sure where to find it written up). Linear-write systems are better than helical.
Just a few thoughts, but this is not an easy issue. You have to understand what you're storing, and how long it has to be readable before you consider an actual medium for storage.
Re:Storage conditions? (Score:1, Informative)
The CD-Rs were stored in a humidity controlled closet away from light sources. Still most of the CD-Rs were unreadable in under two years. Clearly storage conditions are not a factor.
Re:That makes me wonder (Score:5, Informative)
Re:but something is missing... (Score:2, Informative)
Brand and manufacturer? (Score:4, Informative)
Back when you could still get them, I burned all my important data onto Mitsui golds. They seem to be working still, after sitting around for 5-6 years. Similarly with the Mitsui silvers and Kodak silvers. All these used a pthalocyanine dye, which is supposed to be more stable than the cyanine (and cost more
Which brands are good today? That's rather hard to tell, since even within a single brand you're probably going to find a bunch of different manufacturers, unless you're buying one where the brand is the same as the manufacturer. I've seen tons of different manufactured Sonys; Taiyo Yuden's and Mitsui's showing up as Memorex's (very rare, most of the current ones are Prodisc I think and I've seen a lot of Riteks in the past). 'Made in Japan' seems to be a good sign though, instead of 'Made in Taiwan'.
Personally, I save the cheapo ones for throw-aways. Burn to listen in my car for a while, to mix and match and avoid wear and tear on originals. Scratching them up really doesn't matter, they're not that critical. Anything important I try to keep on (supposedly) more long-lasting media, and that gets handled with care. So far, 5+ year backups have been brought back up and data read without any problems. Whether that'll be true of the more current disks in another 5 years I really can't say.
Break out the Brillo (Score:5, Informative)
This would be as good a place as any to mention TDK's Armor Plated DVD Media [tdk.com], which are supposed to keep on working even after having been scoured with steel wool pads. Also, Verbatim makes a line of scratch-resistant [verbatim-europe.com] CD-R media.
Re:Tape Drives (Score:5, Informative)
Laquer = Bad Idea (Score:5, Informative)
This Site [svbxlabs.com] has been kicked around slashdot lots of times and depicts a man, a dremel, a CD and 30,000 RPM's of angular velocity.
Tape isn't slow. (Score:3, Informative)
Re:Magneto-Optical? (Score:4, Informative)
However, others have noted that real-life disks can have a much shorter life.
Normally I'd reckon that off-brand disks come off the same production lines as name brands, but Maxell currently has a campaign to warn people that some white disks are digitally marked as Maxell, which can lead to a recorder treating a disk as a 4X when it's actually a 1X. So perhaps one should stick with branded products for archival purposes.
TDK claims to be using a more stable cyanine dye now, which should translate to increased storage life.
As a rule of thumb, disks recordable at higher speeds should have a longer storage life than those limited to 1X, since improvement in dye stability is directly responsible for the increased recording speeds.
Re:but something is missing... (Score:2, Informative)
Re:A little history... (Score:5, Informative)
disc label
protective coating (laquer)
Aluminum layer (sputtered on)
data layer (pressed into the next layer when injection molded)
polycarbonate injection molded disc
To vary from this is a violation of the Phillips spec, and you are not allowed to put the Compact Disc logo on the resulting product.
What you probably noticed was the laquer layer was thick when we started making discs, but over the years laquer has improved to the point that only a very thin layer is needed.
If you leave out the laquer entirely, the aluminum oxidates rapidly, rendering the disc useless.
Magneto Optical Is The Way To Go (Score:3, Informative)
The drives can be had for roughly $257 for internal IDE [zones.com]. I didn't shop around hard, but you can get a 5pack of 1.3GB disks for $95 [zones.com] that's about $0.014/MB, not too shabby. They also make high end solutions with 9.1GB disks but the drives are remarkably expensive. If I were more serious about doing backups, magneto optical would be the way to go.
Re:Don't take it too seriously (Score:5, Informative)
Long story short the rule of thumb was like this: Green CDs have a life of ~5 hours. Yellow CDs ~20 hours. The DARK DARK Blue cd's (not light blue, the only brand I know of like this is Verbatim) *600* hours.
The price increases correspondingly as well. I found the best solution was to use blue's for backups and critical things, and regular commodity cd-r's stuff for day to day things.
Re:but something is missing... (Score:3, Informative)
The machine is usually a Sony CD-RW CRX145E, recording at 10X and re-writing at 4X. I have faster burners on other machines, but those are newer, so I can't yet vouch for their quality.
Re:God damn it tell me (which CD-R's not to use)! (Score:3, Informative)
Important details are found in the full article:
http://www.cdrfaq.org/faq07.html#S7-4-1
Re:How about remote online backup? (Score:2, Informative)
Re:but something is missing... (Score:5, Informative)
I've always wondered if this [burning at 1x speed results in better CD's] is actually true or not.. I have yet to see any actual evidence to back up this claim...
Well, head on over to cdfreaks.com [cdfreaks.com] website and take a look at the results of some tests. For the lazy among us, burning at 4x resulted in more C1 errors in every test posted (on page 1, page 2 timed out) than burning at a higher speed (usually 40x, but one test was at 52x). A comment on page 2 indicated on person did 4 tests, and half said burn at high speeds and half said burn at lower speeds. Overall, the small sample of results indicated that burning at low speed usually makes things worse, not better. Surprising huh?
I doubt it... (Score:5, Informative)
The other thing to consider is that DVD-R/+R technology is dropping though the floor. I bought a Pioneer A05 for $320 in January and today the A06 is going for $229. [newegg.com], and remember I bought this thing from the same place I linked to. I don't know how DVD-R is for archival, but my point is that at the rate the technology is falling in price, CD-R may not be around much longer anyway.
In any case, I found a rather excellent guide on the different tyes of CD-R media. It goes over all the dyes, their manufacturers, theoretical lifespans of the dyes, etc. I recommend a visit...
http://www.cdmediaworld.com/hardware/cdrom/cd_dye
Re:but something is missing... (Score:1, Informative)
Slower recording speeds not always better (Score:5, Informative)
Does it matter? Yes. Is slower always better? No.
Rather than re-hash this, please see:
In the CD-Recordable FAQ [cdrfaq.org].Quick summary: higher speeds require a different "write strategy" than slower speeds. Different media formulations are optimized for a particular write strategy, so writing slower than the optimal speed can actually produce inferior results.
The choice of media and recording hardware has to be taken into consideration. In any event, this has relatively little to do with disc deterioration. A disc that's better to begin with won't show the effects of physical deterioration as soon, but if the top lacquer coat isn't as close to air-tight as materials allow, it doesn't matter how you write the disc.
Re:Not surprising, and not new (Score:2, Informative)
set your prefs to mod "Funny" down (Score:4, Informative)
The biggest benefit is that it cuts WAY down on the number of +5 posts, so you can get straight to the key comments if that's all you want. It's cool when the home page says "24 of 215 comments" but when you click in the Funny modifier filters half of them out and you end up only having to plow through 12 :)
Re:but something is missing... (Score:2, Informative)
Actually, thinking about it, I do have a couple of disks that are tough to read, but the fact is they've been like that from day one.
100-200 year CD-R blanks are available (Score:5, Informative)
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MAM-E Gold Ultra [brennershop.de], about Eur. 1.15 each.
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Mitsui Gold Ultra [mitsuicdr-store.com], about $1.60 each.
Kodak used to be in this market, but seems to have exited it.The key here seems to be dye type. Phthalocyanine has slower writing speeds but longer storage life; Cyanine has higher writing speeds but much shorter storage life. The "archival grade" CDs also have gold reflecting layers and a tougher substrate.
There are also "Medical grade" CD-R blanks, but they're essentially the same as the archival ones.
There are programs which will read the ATIP information from a blank, telling you what the manufacturer, max writing speed, and dye type is.
Re:simple (Score:4, Informative)
All archival quality CD-R's use phthalocyanine, it is the only stabilized dye known to last more than 100 years. Gold is the absolute best reflective layer available because it is almost completely non-reactive.
The combination of those two is the only way to get a true 200 year archival life CD-R. They aren't "cheap", usually less than a dollar each but 85 cents in a 100 pack isn't unusual. Try this google search [google.com]. The second link is a place selling 100 packs for $82. That's 82 cents a piece for a CD-R that should last until the year 2200.
If you're willing to live with slightly less... I managed to pick up a pack of Fuji CD-Rs with a phthalocyanine dye layer and aluminum reflective layer. Fuji seems to think they will last 100 years, but I have my doubts. Still the #1 reason CD-Rs fail is the dye layer, not the reflective layer.
Xerox has gone to all the trouble. (Score:3, Informative)
According to this ancient Seybold report [seyboldreports.com], Dataglyphs can achieve densities of a kilobyte per square inch.
DataGlyphs were featured in this /. article about chess playing scanners [slashdot.org].
Re:that's not good enough. (Score:5, Informative)
MAM-E Gold Ultra CD-Rs are guaranteed by the manufacturer to last for at least 200 years. [mam-e.com]
Re:simple (Score:3, Informative)
Both Fuji and Memorex have TY and non-TY discs. But you can, as you say, check the packaging for the country of origin. As far as 50- and 100-spindles go, every "Made in Japan" I've bought from these two brands has been TY, as reported by CDR Identifier [google.com].
--
Dum de dum.
Re:Unanswered Questions (Score:3, Informative)
Mitsubishi and TY (Score:5, Informative)
From a little googling, I now see that they signed a Memorandum of Understanding with the Rainforest Action Network promising to change their ecologically unfriendly corporate practices. Here is the link:
http://www.ranamuck.org/news7.01mitsi.htm [ranamuck.org]
Provided the humungous Mitsubishi zaibatsu is living up to their promises, I have no problems now recommending Mitsubishi Chemical CD-Rs. Everything I said about TY goes double for their disks.
The reasons why TY and Mitsubishi CD-R blanks are so good and so compatible are the fact they use a much darker dye than the Taiwanese manufacturers do. Yamaha suggested the use of Mitsubishi Chemical CD-Rs with their "Disc T@2"-equipped burners because the graphics would show up better. They are a better choice for maximum compatibility for the same reason they are a better choice for "Disc T@2". The more visible the dye layer is to the naked eye, the more visible the dye layer is to a CD-ROM or CD player's laser.
I wish I could back my assertions up with a whole list of studies, but I am basically speaking from several years of my own experience with CD-R blanks. I don't see as many CD-Rs made by TY going bad as no-name Taiwanese crap does.
Forget 20 months, check out what 20 days will to. (Score:2, Informative)
check out the results:
http://www.techfreakz.org/cdruv/ [techfreakz.org]
These are name brand CDR's exposed to the
sun for only an hour or two each day.
(mod this up guys, people need to be warned).
Taiyo Yuden (Score:4, Informative)
Taiyo Yuden were reckoned to be the best manufacturer. they make discs for lots of different manufacturers, but you don't know 'til you get home and get yr CD writing software to read the code off the disc and tell you who the manufacturer is, bcos it aint gonna tell you on the packet. and different sub models of disc can be made by different manufacturers.
I think TDK even had the same models, with some made by Ritek (the worst quality) and some made by Taiyo Yuden. there was a court case against them for this.
I buy a single TDK disc, take it home and check it, and if its made by Taiyo Yuden I go back and buy loads of that same model disc, and have been able to get the people in the shop to say they'd take the discs back if they weren't Taiyo Yuden (a large consumer-space chain in the UK, I shan't name them incase they read this and stop being so remarkeably fair)
Re:Unanswered Questions (Score:3, Informative)
And here is the key.
I've seen other tests where CD-Rs can't be written reliably after sitting around blank for a few years or artifically "flash aged" using elevated heat &c.
That matters to me a bit, but what's much more important is how reliable the data can be read after *being written*, then stored for years.
I use Kodak pseudo-golds (they don't make the real gold on gold ultima anymore) for anything I care about. The discs should be good, but they are also actually made by Kodak. No problems with the manufacturer changing & the brand remaining the same. No research on who's selling the best Taiyo Yudens this week needed.
Oh, shit! Good things never last. Well, the folks I bought my last batch of Kodak's from have a replacement: Mitsui Golds [inkjetart.com]
I don't abuse my "archival" discs, so I don't care much about scratch-resistance, which is all some "life" discs offer. I care about bit rot.
Re:Which CD-R(W) brands are worth getting? (Score:5, Informative)
Re:Taiyo Yuden (Score:3, Informative)
In reality, 50% of the TDK discs I buy (model: CD-R80, currently with an item code of CD-R80CMEB but many other items codes too) are manufactured by Taiyo Yuden and 50% claim to be manufactured by TDK
These articles should be useful...
'CD Factories':
http://www.cdmediaworld.com/hardware/cdrom/cd_fac
'CD-R Quality':
http://www.cdmediaworld.com/hardware/cdrom/cd_qua
'TDK Inferior Quality CD-R's':
http://www.cdmediaworld.com/hardware/cdrom/cd_tdk
(Thanks for the tip on an alternate way to find TY discs)