1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Media shelf life

Discussion in 'Digital photography' started by normchevy, Feb 14, 2006.

  1. normchevy

    normchevy Member

    Joined:
    Feb 10, 2006
    Messages:
    16
    Likes Received:
    0
    Trophy Points:
    11
    Can anyone give me some insight as to the shelf life of DVD's /cd's. I am in the process of backing up my old 35 MM negatives to DVD but have heard lots of people saying that DVD's are only good for x annount of years.
     
  2. ireland

    ireland Active member

    Joined:
    Nov 28, 2002
    Messages:
    3,720
    Likes Received:
    16
    Trophy Points:
    68
    Burned CDs Last 5 years Max -- Use Tape?

    Posted by CmdrTaco on Tuesday January 10, @11:16AM
    from the been-there-before dept.
    Data Storage
    Lam1969 writes "Computerworld has interviewed Kurt Gerecke, an IBM storage expert and physicist who claims burned CDs only have a two to five-year lifespan, depending on the quality of the CD. From the article: "The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data 'shifting' on the surface and thus becoming unreadable to the laser beam." Gerecke recommends magnetic tapes to store pictures, videos and songs."

    Storage expert warns of short life span for burned CDs
    And don't count on hard disk drives for long-term storage, either

    News Story by John Blau

    JANUARY 10, 2006 (COMPUTERWORLD) - Although opinions vary on how to preserve data on digital storage media, such as optical CDs and DVDs, Kurt Gerecke, a physicist and storage expert at IBM Deutschland GmbH, takes this view: If you want to avoid having to burn new CDs every few years, use magnetic tapes to store all your pictures, videos and songs for a lifetime.

    "Unlike pressed original CDs, burned CDs have a relatively short life span of between two to five years, depending on the quality of the CD," Gerecke said in an interview this week. "There are a few things you can do to extend the life of a burned CD, like keeping the disc in a cool, dark space, but not a whole lot more."

    The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data "shifting" on the surface and thus becoming unreadable to the laser beam.

    "Many of the cheap burnable CDs available at discount stores have a life span of around two years," Gerecke said. "Some of the better-quality discs offer a longer life span, of a maximum of five years."

    Distinguishing high-quality burnable CDs from low-quality discs is difficult, he said, because few vendors use life span as a selling point.

    Hard-drive disks also have their limitations, according to Gerecke. The problem with hard drives, he said, is not so much the disk itself as it is the disk bearing, which has a positioning function similar to a ball bearing. "If the hard drive uses an inexpensive disk bearing, that bearing will wear out faster than a more expensive one," he said. His recommendation: a hard-drive disk with 7,200 revolutions per minute.

    To overcome the preservation limitations of burnable CDs, Gerecke suggests using magnetic tapes, which, he claims, can have a life span of 30 to 100 years, depending on their quality. "Even if magnetic tapes are also subject to degradation, they're still the superior storage media," he said.

    But he's quick to point out that no storage medium lasts forever and, consequently, consumers and business alike need to have a plan for migrating to new storage technologies.

    "Companies, in particular, need to be constantly looking at new storage technologies and have an archiving strategy that allows them to automatically migrate to new technologies," he said. "Otherwise, they're going to wind up in a dead end. And for those sitting on terabytes of crucial data, that could be a colossal problem."
    http://computerworld.com/hardwaretopics/storage/story/0,10801,107607,00.html
     
  3. arcanix

    arcanix Active member

    Joined:
    Oct 17, 2004
    Messages:
    2,918
    Likes Received:
    0
    Trophy Points:
    66
    That's bs. I have several burned cd's that are older than 5 years, all of them work perfectly, even the cheap media.

    Buy good quality dvd's, and burn them with lowest possible speed to ensure good result. Store them in a dry and dark place, and they'll last longer. If you're paranoid, then you could re-burn those every now and then.
     
  4. DoWright

    DoWright Guest

    Copied from Optical Storage Technology Association http://www.osta.org/technology/cdqa13.htm

    DISC LONGEVITY
    [bold]What is the shelf life of unrecorded CD-R and CD-RW discs?[/bold]
    The unrecorded shelf life of a CD-R or CD-RW disc is conservatively estimated to be between 5 and 10 years.

    [bold]How long will data recorded on CD-R and CD-RW discs remain readable?[/bold]
    The life span of a written disc depends upon a number of factors including such things as the intrinsic properties of the materials used in the disc’s construction, its manufactured quality, how well it is recorded and its physical handing and storage. As a result, the life span of a recorded disc is extremely difficult to estimate reliably. However, to calculate disc life spans within some practical timeframe blank media manufacturers do conduct accelerated age testing by subjecting samples of their discs to environments much beyond those experienced under normal storage conditions. Generally speaking, only the effects of varying temperature and humidity are considered. These test results are then used to predict how long a disc will remain readable under more normal storage conditions. Since questionable testing and measurement procedures can seriously impact upon and compromise these estimates several international standards have been developed which specify procedures to be used conducting accelerated testing and analyzing the resulting data from prerecorded (pressed) and recordable CDs:

    ISO 18921:2002, Imaging materials — Compact discs (CD-ROM) — method for estimating the life expectancy based on the effects of temperature and relative humidity

    ISO 18927:2002, Imaging materials — Recordable compact disc systems — method for estimating the life expectancy based on the effects of temperature and relative humidity

    For years now many media manufacturers have performed their own lifetime evaluations using these or a variety of other homegrown tests and mathematical modeling techniques. Historically, manufacturers have claimed life-spans ranging from 50 to 200 years for CD-R discs and 20 to 100 years for CD-RW. Be aware, however, that disc producers, manufacturing methods and materials change over time as do applications and cost imperatives. Consequently, those concerned with disc longevity should consult the appropriate international standards and their media manufacturer for more particular information.

    It is important to remember, however, that nothing lasts forever and that technologies inevitably change. Well-designed products, such as CD-R and CD-RW, allow for seamless transition to the next generation and ultimately, since they embody digital information, contents can be transferred to future storage systems as becomes necessary to preserve whatever has been stored on the discs.
     

Share This Page