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Data Storage Hardware Technology

Say Goodbye To Your CD-Rs In Two Years? 707 707

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."
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Say Goodbye To Your CD-Rs In Two Years?

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  • by KingRamsis (595828) <kingramsis@gma i l .com> on Sunday August 24, 2003 @09:00AM (#6777008)
    the speed in which the CDR is burned sometimes it makes a difference, for the highest reliability I think 1x is the best.
    • by kryptkpr (180196) on Sunday August 24, 2003 @09:16AM (#6777070) Homepage
      I've always wondered if this is actually true or not.. I have yet to see any actual evidence to back up this claim.

      It doesn't really matter how fast the reading laser moves along the media, so why would it matter how fast the recording laser moves?
      • by SpaceLifeForm (228190) on Sunday August 24, 2003 @09:25AM (#6777106)
        If you burn the CD at slower speeds, the laser has more time to burn better pits in the media.
        • Indeed; I have CD-Rs over 5 years old, and I have several sets of CD-RWs which have been routinely overwritten on a grandfather/father/son basis for 4 years, and not a single coaster among them.

          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.

          • Same here, I have CD-R's from my Ricoh CDRW (the first one on the market) that are now 6 1/2 years old and all of them that aren't scratched to hell are still readable. I wonder if this isn't indicitive of a falloff in quality of blanks. Back then blank CDR's were over a buck a piece and to get ones that would read in most normal cdrom or audio players you had to pay around $4-5 a piece, now you can get CD-R's for around 5 cents a piece. Obviously scales of economy have dropped the price but I'm wondering i
      • by KingRamsis (595828) <kingramsis@gma i l .com> on Sunday August 24, 2003 @09:51AM (#6777187)
        You can do the experiment, but you will need a cheap-o-media try burning at 1x and then at the maximum your CDR drive can handle, and try it on a variety of CD-ROM drives, the odds that the 1x copy will be readable on more drives.
        I still have a SONY CDR burned at 1x in 1997 ! and still works just fine. (but useless old software anyway)
      • by Spazmania (174582) on Sunday August 24, 2003 @10:55AM (#6777456) Homepage
        Do you remember science class where they told you a measurement wasn't correct unless it included a +/- error estimate?

        Every CD burner (like every real-world device) has a certain amount of error. The device decides to turn the laser on or off, and there is a delay before the laser turns on or off. This small delay varies with heat and other factors within the device and varies with the component tolerances from device to device.

        This error rate is over time, not distance. So, if the CD is rotating slower, it doesn't move as far during the error period. This results in a burn which is closer to perfect, that is it has less error distance than a higher speed burn.

        Then there is the completeness of the burn; with a brand new good quality drive it shouldn't matter, but how many of you have a brand new plextor?

        And of course there's also the CD media. If you bought the 10 cent bulk discs and expected them to last, shame on you. I record at slow speed to the old dark-blue verbatims whenever I can, and after 7 years I havn't lost data yet.
      • by berzerke (319205) on Sunday August 24, 2003 @12:48PM (#6777934) Homepage

        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?

        • It actually depends on the drive. I remember back in the day when Adaptec Easy CD Creator put out a regular newsletter and discussed this. The older drives would produce less crc errors at slow speeds. Newer high speed drives will do better at high speeds because that is what they are designed for. The higher speed drives are only calibrated at the top speed burns.

          BTW, I had some audio cds stored in my car that lasted over 5 years. I finally threw 'em out because they started skipping on some tracks.
    • by FirstOne (193462) on Sunday August 24, 2003 @09:51AM (#6777190) Homepage
      "But something is missing, The speed in which the CDR is burned sometimes it makes a difference, for the highest reliability I think 1x is the best."

      I agree.. Slower recording speeds will usually improve the contrast ratio of the resulting recording.
      One can confirm this by making several cd-r's writing at different speeds using the same type of media, and then visually comparing the cd-r's data surfaces, (For recorded areas, Darker is better).

      A fair number of CD recording programs DO NOT have a VERIFY cd-r contents option after a burning, and is a major pain in the ass. This problem got me good when I used some 12x Office Depot media for saving some TV show mpegs. Bad move,
      I found out months later, that 50% of initial recordings had one or more non recoverable bad spots. :-(

      Nero is the only mastering program I know of, which will verify cd-r contents after burning :-),
      But it doesn't do it for all recording formats :-( .

    • by fadden (469243) on Sunday August 24, 2003 @01:29PM (#6778178) Homepage

      Does it matter? Yes. Is slower always better? No.

      Rather than re-hash this, please see:

      Subject: [3-31] Is it better to record at slower speeds?
      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.

  • Oh no! (Score:3, Funny)

    by zebs (105927) on Sunday August 24, 2003 @09:00AM (#6777010) Homepage
    My pr0n my precious precious prOn!
    • Re:Oh no! (Score:3, Funny)

      by Cpt_Kirks (37296)
      Damn, your're right!

      Does DVD-R last longer? Let's see, I'll need about 200 blank DVDs...
    • Re:Oh no! (Score:3, Funny)

      by AntiOrganic (650691)
      You mean you don't back up your porn to your $5,000 autoloading Exabyte SCSI tape drive?
    • Re:Oh no! (Score:4, Funny)

      by mickwd (196449) on Sunday August 24, 2003 @10:28AM (#6777334)
      Yeah, you're CD-ROM drive won't be able to read it any more.....

      .....Maybe it went blind ?

    • Re:Oh no! (Score:5, Insightful)

      by p3d0 (42270) on Sunday August 24, 2003 @11:01AM (#6777485)
      Why does every porn joke get instantly rated "5, Funny"?
      • Re:Oh no! (Score:3, Funny)

        by Bob McCown (8411)
        Why does every porn joke get instantly rated "5, Funny"?

        Priorities, my man, priorities!

      • Re:Oh no! (Score:5, Funny)

        by orthogonal (588627) on Sunday August 24, 2003 @11:18AM (#6777565) Journal
        Why does every porn joke get instantly rated "5, Funny"?

        I'd explain, but it takes too long given that I'm typing one-handed.
      • Re:Oh no! (Score:5, Insightful)

        by Ralph Wiggam (22354) * on Sunday August 24, 2003 @12:13PM (#6777792) Homepage
        Here on Slashdot there are many things that divide us, emacs vs. vi, SuSE vs. Debian, the best Dr. Who, all sorts of geeky crap. There is one thing that unites us all- our love of pornography.

        -Barry
        • Re:Oh no! (Score:3, Insightful)

          by silhouette (160305)
          There is one thing that unites us all- our love of pornography.

          What a silly thing to say. Taking it seriously for a moment - There are lots of people who disapprove of pornography, for one reason or another. The political left (feminism) considers it exploitative, the political right (conservative religious) consider it amoral, and women (even geek women) don't tend to be consumers of pornography. Since Slashdot certainly has its share of political left, right, and women, it's easy to see that no one t
          • Re:Oh no! (Score:3, Insightful)

            by SomeGuyFromCA (197979)
            > Since Slashdot certainly has its share of political left, right, and women, it's easy to see that no one thing will EVER unite ALL Slashdot readers.

            Sure there is. Our love of bandwidth.
      • by ChrisCampbell47 (181542) on Sunday August 24, 2003 @01:43PM (#6778241)
        Slash has a user preference that you can set to mod "Funny" down. So if you're tired of seeing the adolescent humor that the Slashdot crowd thinks is "Funny", just apply a -2 or -3 to all "Funny" posts.

        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 :)

        • I have my filters set up to give a -5 to all posts, and I browse at 3+. I can read all the comments on a dozen articles in less than a minute now.

          What's really strange is that ever since I excluded all of the articles from the front page, slashdot doesn't seem to ever update anymore.

          Needless to say, my productivity has gone through the roof.
  • simple (Score:3, Informative)

    by frodo from middle ea (602941) on Sunday August 24, 2003 @09:00AM (#6777011) Homepage
    Take multiple backups and atleast have one backup on high quality CD-Rss not the 25c a piece ones.
    Keep upgrading your Harddisk from time to time and backup data from old HD to new one.
    • Re:simple (Score:5, Interesting)

      by LostCluster (625375) on Sunday August 24, 2003 @10:29AM (#6777338)
      Do a full backup once a year and a 20 month lifespan for the media doesn't matter...
  • Happened to me (Score:2, Informative)

    by j_dot_bomb (560211)
    Almost all of my no-name disks are dead after 3 years. Some of my verbatims are dead to. Hard disks at 1/gig now seems cheap compared to my dvd writer and 20c per gig disks. My bet is those optodisk-RW will be dead in two years.
  • 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.

    • by sabNetwork (416076) on Sunday August 24, 2003 @09:12AM (#6777053)
      >treat them like a mushroom and keep them in the dark.

      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.
      • error stats (Score:3, Interesting)

        by xyote (598794)
        SCSI tape drives, most of them, even the low end ones, always had a way of reading the error statistics for tape reads and writes. So in theory, because no tape software actually uses this info, you could get advance warning that a particular tape was deteriorating before you got to the point of non-recoverable errors.

        I suspect that CD drives also have this capability, just that software doesn't bother to use that info. Actually, most software doesn't even appear to check for non-recoverable errors so I

  • by fredopalus (601353) on Sunday August 24, 2003 @09:04AM (#6777023) Homepage
    Lots and lots and lots and lots and lots and lots of floppies.
  • by fredrikj (629833) on Sunday August 24, 2003 @09:05AM (#6777027) Homepage
    Just put your stuff on an FTP site and let the world do the backup for ya.
    • by Jugalator (259273) on Sunday August 24, 2003 @09:23AM (#6777097) Journal
      Or put it in your Kazaa folder and give the filesi maginative names like "horny young teen sex party.mpg", etc... You need to maintain a porn name real name table though in case you'll need the backups again. :-)
      • +Funny, yes. But it might actually work when you embed the data into real pictures/movies. The technique of embedding is known as "steganography", and sometimes also as "digital watermark".

        Scramdisk was an open source program to create encrypted containers (mount as driveletter in windows) in .WAV files. You could choose to use only the lower 4 bits (WAV 4x as large as hidden data) or the lower 8 bits (WAV 2x as large as data).

        Be the first to post a FLAC (lossles audio compressor) of the next hot EMINE
  • All of mine from the 80's and 90's still work.
  • Tape Drives (Score:5, Insightful)

    by nilstar (412094) on Sunday August 24, 2003 @09:06AM (#6777030) Homepage
    Well - if you recall tape drives were the "big thing" in backup about 5-10 years ago. I have looked at 10 year old tape backups & they work just fine. Maybe we need to trust good old reliable tapes. Or the other (faster) solution would be external hard drive backups.
  • by Ragnagnor (682349) <kwantumfisiks@@@hotmail...com> on Sunday August 24, 2003 @09:07AM (#6777032)
    Just do what I do : buy a rack, install in front of your machine (under the DVD or CD-RW or somewhere) and back up all your important data (or your entire harddrive) to a separate harddisk. Prices on smaller models (40-60 gigs) aren't all that steep, and most people I know have trouble just filling up their 'small' 20 or 30 gig drives. A spare 60 gigger rackdisk will keep you satifsied for a long time... Alternatively you could also just buy an external fire-wire or USB harddisk, although I don't really have all that much experience with those kind of devices.
    • by B747SP (179471) <slashdot@selfabusedelephant.com> on Sunday August 24, 2003 @09:31AM (#6777132)
      most people I know have trouble just filling up their 'small' 20 or 30 gig drives.

      With respect Sir, most people you know don't download nearly enough pr0n.

    • by Arbogast_II (583768) on Sunday August 24, 2003 @09:44AM (#6777166) Homepage
      The CD is an inferior storage technology that has propagated due to 3 reasons IMO.

      1. For the average person, a file is in some way less real if it is on a hard drive, and more real if it is on a CD, where it is a physical object they can touch.
      2. Familiarity with CD's due to long term use on music CDs.
      3. Vastly superior marketing to hard drives.

      Removable hard drive bays should be standard on all PC's. Once you are used to these, the Hard Drive is just a Cartidge to plug into the PC. Data is easily backed up, and a Hard Drive in closet is safe.

      Hard drives are faster, take up less space, and are very cost competative with CD's. I am unclear why CD's are popular with the tech savvy crowd. It's an inferior storage technology.
      • by Idarubicin (579475) <allsquiet AT hotmail DOT com> on Sunday August 24, 2003 @10:41AM (#6777375) Journal
        Hard drives are faster, take up less space, and are very cost competative with CD's. I am unclear why CD's are popular with the tech savvy crowd. It's an inferior storage technology.

        I can put a CD in its jewel case, then drop it off a desk and on to a concrete floor--and I can expect the data to still be intact.

        Hard drives are impact sensitive, and still prone to failure after a year or two.

        Also, if I need to move a file from point A to point B CDs are convenient and lightweight--everybody has a CD-ROM drove. Subsequent to that, many people prefer to make backups to CDs because they are a technology that they already have installed for other reasons. Rhetorical question by hypothetical individual: Why would I go to the trouble and expense of another backup method when I already have a CD burner?

        Bad CDs also make excellent coasters.

      • by LostCluster (625375) on Sunday August 24, 2003 @10:42AM (#6777379)
        I don't consider a backup copy kept within 3 yards of the original copy to be a real backup. Afterall, the point of a backup copy is to survive whatever clamity may befall the original copy.

        So please, don't call an HD that is in the same computer, or even the same server rack, your backup. However, a network connected machine on the other side of your building will do just fine.
        • by AKnightCowboy (608632) on Sunday August 24, 2003 @10:49AM (#6777417)
          So please, don't call an HD that is in the same computer, or even the same server rack, your backup. However, a network connected machine on the other side of your building will do just fine.

          That's what I tried telling those RIAA bastards but they won't believe me. Putting my CD backups on Kazaa was simply the safest backup investment I could've ever made. Then they came along and labelled me a pirate! A pirate!? I'm just trying to backup my valuable data! Where better than in a distributed format strewn all across the Internet? Even if the entire United States were to blow up I could still retrieve my data from China! Please RIAA, think of the backups.

        • It depends on your need for security, of course, but many, even rather small businesses, opt for off-site storage. In a way the idea storage would be at a remote network host...but you would need to worry about THEIR backup policy, also about encryption and access to your private keys.

          It's no longer a hard problem, but everyone seems to have decided that they already know the correct solution ... so the best available ways aren't being tried.

          OTOH, just imagine what a huge surge of bytes that would put on
  • Easy backups (Score:5, Interesting)

    by glesga_kiss (596639) on Sunday August 24, 2003 @09:08AM (#6777033)
    Simply buy twice the number of drives you need, and do an rsync between the two sets now and again. For added safety, get a friend with broadband and store the second box there. Then you are safe from fire, theft, drive crashes etc, with minimal effort to keep the backup up to date.
  • Storage conditions? (Score:5, Interesting)

    by T-Kir (597145) on Sunday August 24, 2003 @09:08AM (#6777034) Homepage

    I've got a whole load of burned CD's that I created up to about 5 years ago.. and on varying quality of media, and a lot of them aren't any problem.

    I suppose storage is the key thing, keep them in a dark cool place will help them last just that bit longer (unless you have a case of those little bugs that like eating the data layer).

    Although they are of a similar tech, what about DVD recordable disks? I've got plenty of those now... but if I keep doing what i've been doing over the years and backup my backups onto newer media then I'm not too worried.

    Just my $0.02

  • by xanderwilson (662093) on Sunday August 24, 2003 @09:08AM (#6777036) Homepage
    This doesn't tell us much. It's almost a teaser. "Are you going to die tomorrow? The answer may surprise you. Stay tuned for News at 11." I have some CDRs that stopped working within days and others that have lasted over 4 years now--same brand from the same spindle even. I wonder if the full Dutch article gives specifics or if they found _any_ CDs that were still working fine after twenty months. The teaser seems to suggest that they're all terrible. I do know that I get fewer duds now that I use Toast than I did when I used "Easy CD Creator." Beyond that, I don't know anything that makes a difference. CDRs stop working. DVD-Rs are crazy fragile. Hard drives fail. Paper burns. Maybe my data wasn't supposed to last forever. Alex.
    • 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

  • Save it to Film (Score:3, Interesting)

    by notestein (445412) on Sunday August 24, 2003 @09:18AM (#6777076) Homepage Journal
    Save it to film. [kodak.com]
  • by tgv (254536) on Sunday August 24, 2003 @09:19AM (#6777082) Journal
    The online summary of the article says literally: "Uit onze steekproef blijkt dat er veel rommel op de markt is. We hebben cd-r's aangetroffen die nooit op de markt hadden mogen komen. Het gaat daarbij mogelijk om afgedankte partijen."

    Or, rather literally translated into English: "Our sample shows that there is a lot of junk on the market. We have found cd-rs that should never have been for sale. Possibly it concerns rejected batches." Which suggests to me that the correct heading of this article should be: CD-Rs are like everything else: you get what you pay for.

    • by Monkelectric (546685) <slashdot&monkelectric,com> on Sunday August 24, 2003 @11:50AM (#6777705)
      yes sir. Forgive me for this information is all off the top of my head, but I did quite alot of research for my work when we needed to choose a brand of cdr's to backup with. CD-R Life is measured in Something-hours. I forget what "something" is, but its the name of the lazer that reads the cds, and what it means is the disc can be exposed to so many hours of that laser light before it is unreadable.

      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.

  • by DarkZero (516460) on Sunday August 24, 2003 @09:21AM (#6777086)
    What speed was used to write the CDs?
    Were they all stored in the same place?
    Were they all burned by the same CD burner?
    Were they all burned from the same source (a single CD, hard drive, network, etc.)?

    30 CDs sounds like an epidemic, but since they were all burned at the same time twenty months ago, there could be a lot of other reasons why all of these discs would go bad. If they were all burned at the same time, then they're effectively talking about one batch, regardless of how many different CD-R brands were used in that single batch.

    Does the Dutch article cover this or is this just a scare story?
    • by Snover (469130)
      These CDs WERE NOT WRITTEN TO. They were stored on the original spindles for 20 months and then HARDWARE ANALYSED. The CDs were all completely blank.
      • These CDs WERE NOT WRITTEN TO

        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 actuall
  • by Krapangor (533950) on Sunday August 24, 2003 @09:21AM (#6777087) Homepage
    The data layer of a CD-R consists of cynanide or phthalocyanine organic dyes. However these dyes have a orientated electric charge like water molecules.
    Take now into account earth's rotation and its magnetic field. It induces an albeit very slow movement of the molecules - the data layer degradation. The same effect causes btw certain currents in the Pacific oceans. While the movement is very slow and in the case of the ocean not very important, it does cause damage after a certain amount of time in the case of a CD-R. You should remember that the scale of the information storage units on a CD-R is in the nanometer range. The information is just "washed away" in an entropy-like effect.

    However, you can slow this movement down. The molecular movement in the data layer is directed. So it can be reversed to a certain degree just be placing the CD-R the other way around. So, all you have to do is to mark the position of the CD-R in your rack exactly. And reverse it's position every month or so. This can increase to the lifetime of a CD-R about 150 percent. More can't achieved (in normal environment) because electric machines like your computer etc. create their own electro-magnetic fields. And the effects of these varing fields are much more difficult to negate.

    BTW: the 100 percent wrong place to store your CD-Rs is on the top of your CRT.

  • Offsites (Score:4, Insightful)

    by Michael Ross (599789) on Sunday August 24, 2003 @09:24AM (#6777102) Homepage
    Don't forget to have one or more off-site backups (encrypted in case they are stolen). I keep one off-site backup (on CD-RW) in town, at a friend's place, and swap it for a fresh backup every time I visit him. (Be sure to offer to do the same for your friends.) An out-of-state backup gets refreshed every time I visit my folks.

    It's peace of mind knowing that if, heavens forbid, anything catastrophic were to happen to your place of residence, or if burglars were to take your computers and disks/tapes, then you would at least not have completely lost all of your critical data.
  • by Rolo Tomasi (538414) on Sunday August 24, 2003 @09:24AM (#6777104) Homepage Journal
    Mitsui Medical [mediasupplier.com] CD-Rs, for one, are specced for 100 years lifetime.

    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).

    • I haven't had any high quality CDRs go bad on me yet. And by high quality I don't mean your bulk spindles, I mean Mitsui Gold, Tai Yuden, Kodak Gold (no longer produced), Verbatim DatLifePlus (stay away from ValueLifePlus), etc...

      To be extra safe, I run two CD-R drives to write two copies of the data to two different brands of CDR medias at the same time. Then I also overlap the data for the next batch -- taking half the data from the previous CD, and adding new data to fill the new one. So that any given
  • by petrilli (568256) on Sunday August 24, 2003 @09:41AM (#6777153) Homepage
    I used to work for a company in Austin, TX whose speciality was optical drives (not CDs, but WORM mostly), and one of our customers was the National Archives. This was when CD-Rs were just coming out, and the NA was interested in a cost/benefit analysis of whether or not they could replace their expensive 14" WORM systems with cheap CD-Rs.

    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.
    • Did you ever look into CD-RWs?
      They are a phase-change medium, either the substrate is crystalline or it is amorphous. Thats not something that's likely to change with time or degrade like an organic dye.
      • The other poster is correct. While we did not examine CD-RW, as they didn't really exist at the time, and also violated a rule for archiving for the group we were doing work for, which is that you can change them undetectably, I would imagine they suffer from the same problem as other mediums. Panasonic's phase-change designs were excellent, and substantially more stable than MO-RW, but in the end, they were VERY sensitive to UV, which is why they were in cases that had shutters that had interlocks. CD-RWs
        • i *had* several panasonic phase change drives.

          the media and technology is shit. period. it died off for good reason.

          every single one of the discs died within a year with unrecoverable errors under even light occasional use.

          even the crappiest CDR/RW technology I have seen is light years beyond that panasonic phase change crap.

          ps i still have the drive and dead media sitting around, if anyone wants to buy it cheap...
  • by Silh (70926) on Sunday August 24, 2003 @09:58AM (#6777219)
    Too bad they didn't give a list of brands and manufacturers; that would've been good to know.

    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 ... the Mitsuis at up to $5+ per disk at times). Unfortunately I believe they dropped off the CDR market since I can't seem to get a hold of any of theirs, save some which is rebranded under a different name... which you really can't find out until you pop it into the CDR drive to ID it. I believe Taiyo Yuden made a well-stabilized cyanine die that was supposed to last long as well. I can't say much about the stability of the pthalocyanine dyes today, especially all those coming from the cheaper manufacturers (Ritek, Prodisc, etc). It doesn't seem like you can even find gold pthalocyanines anymore these days, or heck, even gold cyanines. I don't know much about the azo dyes though.

    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.
  • Brands? (Score:3, Insightful)

    by jcsehak (559709) on Sunday August 24, 2003 @11:14AM (#6777546) Homepage
    Well, give it up. What brands have you used that are fine, or more importantly, what brands have failed for you? Here's my experience:

    Lesson 1: Never get a CD-R w/o any printing on it. I got some (TDK, I think) that were just silver on the top, no branding or anything, and they burned just fine, but I found out later they could be scratched VERY easily. Scratched on the top, mind you. Apparently there was no protective layer over the foil, and you could just scratch it right off. I think they were meant to be printed on by some kind of CD printer.

    My TDK's that I burned 2 years ago with the white surface (w/ branding) seem to be perfectly fine though. I also don't seem to have any problem with any imations that are as old.

    I have one 2-year-old CD in which the foil appears to be harboring some kind of fungus. The brand is "K Hypermedia," I think I got it for free or really cheap. You probably get what you pay for. But the "fungus" is only on part of the edge, so it still plays fine. I have a handful of others of the same brand, which look okay.

    disclaimer: I take semi-good to pretty-bad care of my CDs. They are routinely left out on the counter, desk, or wherever, and sometimes stacked in tall piles, when I don't feel like looking for the matching packaging.
  • by jone1941 (516270) <jone1941 AT gmail DOT com> on Sunday August 24, 2003 @11:20AM (#6777576) Homepage
    According to this site [mo-forum-asia.com] that was linked to from Fujitsu's site [fujitsu.com] magneto optical drives are nearly indestructable, they have a minimum life of 30 years (good enough for me) they don't lose their magentic properties until they reach 180C so you can spill as much coffee on them that you want. =P

    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.
  • Paper (Score:3, Insightful)

    by menscher (597856) <menscher+slashdot @ u iuc.edu> on Sunday August 24, 2003 @12:25PM (#6777835) Homepage Journal
    Why is everyone surprised? The only means of data storage that has been tested to last 100+ years is to write it out to paper. For extremely critical stuff, it's typically printed in a small font on acid-free paper, then stored in a climate-controlled vault.
  • I doubt it... (Score:5, Informative)

    by retro128 (318602) on Sunday August 24, 2003 @12:59PM (#6778009)
    I remember way back when, around when CD-R's first came out, they had a type of organic dye that appeared gold whos purpose was for data archival. I have a few of these and quite a few of the old blue Verbatims and some no-name green media. All of these are still quite readable, and they were burned in 1996. Perhaps one of the reseachers in the article left their CD-R's on the dashboard of their car and didn't own up to it.

    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. shtml [cdmediaworld.com]
  • by Animats (122034) on Sunday August 24, 2003 @02:05PM (#6778352) Homepage
    Archival quality blanks exist, but they're hard to find and cost more. Some sources: 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.

  • Taiyo Yuden (Score:4, Informative)

    by thegoldenear (323630) on Sunday August 24, 2003 @03:32PM (#6778792) Homepage
    a while back http://www.cdmediaworld.com/ [cdmediaworld.com] had an article explaining how there were something like 256 different brands of CD media, but only something like 16 different manufacturers of the actual media.
    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)

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