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Storage: Do burned CDs and DVDs have a shelf life?
- 2/13/09 2:55 PM
olds dvd\cds
by lizardo_manson - 1/30/09 8:06 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
I don't know an exact end date for cd\dvd media but in my case i have dvds and cd from moret han 3 and a half year and still working great, but one of the cd have a strange black thing that looks like a worm, very weird but still working. But better to keep doing copies of important data just to avoid any problem in the future.
Yes but it varys with media
by magnusfl - 1/30/09 8:24 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
Most media can easily go over 10 years and in proper storage conditions much longer and some archival quality disks can do fifty years so the best bet is to re-burn your critical data such as pictures every 10 year onto new media however you find most of your back up disks are now irrelevant such as old programs and games
The main issue with the disks is oxidation which is why Archival quality disks use gold which is also unaffordable for common use.
From memory
by wwaldok - 1/30/09 8:30 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
I recall reading an article several years ago (6 to 8 years?) addressing this same question. An apparently qualified lab technician stated that a burned CD-R stored (undisturbed) in a relatively stable environment of 65F - 75F, non-condensing humidity, in the dark, in a chemically neutral (normal) environment, and under negligible mechanical pressure or stress could be expected to have a shelf life of between 70 and 100 years. There was some doubt that a burned CD-RW would have as long of a shelf life as the burned CD-R. There was no comment regarding DVDs but magnetic tape and floppy discs were both expected to have a considerably shorter life than the CD-R. I can't recall the article or publication that this information came from but it was not sourced from the internet. But...you should await confirmation from others before counting on this information.
Burned CD and DVD do have shelf life
by wjunwei - 1/30/09 8:31 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
Im a person with material engineering background. The shelf life is dictated by adhesive coating of the disc, the degradation rate of the plastic substrate, the moisture exposure condition. Hence, typical 1~5yrs.
Eg1. CD and DVD stored in a dry box will degrade faster as the adhesive layer peel off easily.
Eg2. CD and DVD with special label print or marker mark may have its coating peel off easily as it has gone through an additional heat process (which could causes peeling)
Eg3. CD and DVD which are made of poorer quality plastic substrate will lose it material (optical properties) at higher rate. This wont be visible to human eyes.
One tip: Thos Old CD that couldnt be read, can be read (for about 30mins) if they are soak in water. What i normally do is advise my friends to use detergent to "clean" the top surface. I told this solution so as to save breath explaning on the material engineering stuff.
Do burned CDs and DVDs have a shelf life?
by explorer2_000 - 1/30/09 8:50 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
What your friend said was true. However the shelf life of products can vary dramatically. Like your Grandma said, "You get what you pay for".
I have seen cheap CDs with the reflective layer flaking off the disks right out of the box! The last batch I bought was a Post Office brand and once again there were a few duds in that batch right out of the box. How long do you think these will remain fiathful?
Aim for a premium quality name brand if you are placing important data on them for long term storage but ten years is pushing the limits a bit. If you are looking for long term reliable storage of data, you are living dangerously. Time to rotate to a new set of media.
The burning process emulates the lands of an actual pressed optical disk by laser etching on a dye layer or similar and naturally this media will have a finite lifespan as this recording layer degrades with temperature over time. This will vary with the ambient storage conditions. Exposure to high temperatures and light will shorten that lifespan considerably. Burning disks at a low speed will achieve a more effective and therefore more stable media write. Recordable media is much more stable than Rewritable media.
Doing a Data Restore test every so often to verify the integrity of your backup is a good idea. Gives you peace of mind to know you are actually achieving something tangible and not just doing it for the psychological benefits.
I live in a very hot humid climate myself so if I were using optical recordable media, I would go with quality and renew the media at realistic intervals of say 5 years or so to be safe. When I used to back up to optical recordable media many years ago, I opted for the best and chose the Kodak brand but Verbatim is also reliable. You will have your own premium brand in your own locality. They will be the more expensive ones at double the price of the cheap crap.
But assuming you have a USB2 port on your PC and given the very low price of an external hard drive these days, would it not be far more economical and reliable to backup to one of these?
Bad press: http://au.youtube.com/watch?v=pNRuLD7jEbU
Good News: http://www.mscience.com/faq53.html
Google "cd dvd lifespan" and you will get a wealth of information .... and confusion. Reading the above it appears that the dye layer degradation problem has now been solved and is no longer a concern as it was when I was using optical backup media.
Now concerns rest with the polycarbonate disk itself - physical distortion and degradation of the disk over time. I know that window glass will "flow" over time and the surface will become rippled with waves - wonder how polycarbonate stacks up?
Manufacturers will quote figures from simulated accelerated lab testing - these are not real world figures and it would be wise to err on the side of caution. And lets face it - call me a cynic, but these figures are bound to be best dressed to promote consumer marketing.
Adopt a common sense mindset and IF you are using quality media and IF you adopt sensible storgae and handling practices, you would think that ten years would be a reasonable expectation. Beyond that I would start to worry.
After 20 years your optical media will be long obsolete in any case and you will have no choice but to move with the times. Such are the growing pains of technology.
Neo.
glass flows??
by PBSandU - 2/13/09 6:50 PM In reply to: Do burned CDs and DVDs have a shelf life? by explorer2_000I hate to put a fine point on this but, this is how wrong info gets exchanged, so let’s keep it strait.
Your assertion of glass is not correct. While you may have heard that it is said that glass is a liquid, which has cooled but is not crystallized, or it just flows fantastically slowly. Well… this is not true. Glass is a true bona fide solid! In support of your assertion that glass is a liquid, people often point out old church windows and see that the glass is thicker at the bottom and waves in the pane of glass. The reason for this is not that the glass has flowed over time… but that medieval glaziers sometimes could not cast perfectly uniformed sheets of glass. When this happened, they preferred to stand the glass with the thickest part at the bottom for obvious reasons.
The confusion about whether glass is a liquid or a solid probably came from a misreading of the work that German physicist Gustav Tammann 1861-1938), who studied glass and described it’s behavior as it solidifies. Gustav observed that the molecular structure of glass is irregular and disordered, and unlike the neat arrangement of molecules in, for instance in metals. Gustav, reaching for an analogy, he compared it to a frozen super cooled liquid. Saying glass is like a liquid does not mean it IS a liquid.
Today solids are classified or categorized as either crystalline or amorphous. In short… glass is an amorphous solid. Polycarbonate is too a solid. It will not flow until it is at it’s melting point temperature.
glass flows
by Sanford Scholton - 2/13/09 9:02 PM In reply to: glass flows?? by PBSandUThe trouble with your logic is that I have seen many plain glass windows in old homes (1890's) that are thicker on the bottom. Many science books (I haven't read them all) will state that glass will flow.
Glass doesn't flow
by David Walland - 2/15/09 2:31 AM In reply to: glass flows by Sanford ScholtonMy wife is a Glass Artist and goes absolutely mad whenever this misinformation about glass is "quoted".
Until the 1950s all window glass was made by some sort of blowing or rolling process. Plate glass was made by quite literally polishing flat surfaces on this glass. This means that window glass was always a bit wobbly, simply because it was impossible to make it optically flat.
It's quite right that there is no discernable movement of glass in centuries. Recently, Roman glassware nearly 2000 years old has been recovered from a wreck. It remains as it was made and shows no signs of flow over time. There are good scientific and engineering reasons for this, relating to bond strength.
In any case, this doesn't help when considering the plastic used to make CDs and DVDs. I would be surprised if this is technically a glass and it is likely to be much less resistant to the ravages of time than glass.
Thanks to everybody who has contributed to the optical media life-time discussion.
I can see two useful lines for us to take:
1) Use cheap discs for sending out images to people when we want these to be immediately readable but not to have a long life. You'd be surprised how many people can't accept that an artist's work is copyright and will use images for all sorts of purposes, without permission or any right whatever. Of course most artists can't afford to take any action to prevent this theft...
2) Use top quality media, top quality drive and properly designed storage for our own storage of images of her work.
Regards
David
do burned cds dvds have a shelf life
by amg64 - 1/30/09 8:55 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
I believe if its all mixed data there should be no real problem but with backup programs talking to some of my friends and myself we have noticed that after time the cd does not always work so my golden rule is to make master backups and at least 2
Dyes fade with time.
by skelax - 1/30/09 10:02 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
I had a Maxell DVD-R and a Memorex CD-R where I stored some MP3 recordings 4 years ago. When I played them recently, the quality had deteriorated so much. I checked if there were scratches but the discs were so shiny. So I suppose that the dye used on the discs faded somehow that some dark spots became lighter and some light spots became darker simulating "Ones" and "Zeroes". So I usually burn a disc at a lower speed than the rated speed of the disc to make the burning more intense and preserve the data longer. However if you want your data to last, flash drives are more permanent than discs since they use circuitry that open and close as current is passed through them and stays that way unless you pass another current. The downside is that flash drives are more expensive than discs.
Media shelf life? Worry more about changing formats.
by k3man - 1/30/09 10:24 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
About 2 years ago I also had the same concerns, so I did some research and this is what I was told by the various storage media makers. Unlike prerecorded cd/dvds, most recordable ones sold for consumers use a type of dye (cyanide I Believe) that is altered by the laser in your drive during the writing process. Over time this dye begins to break down and quality of data can/will be lost. Most manufactuares I spoke with recommended making copies every 5 years or less. The exceptions were the more expensive archive cd/dvd's that use a different type of dye. Kodak Gold is one example. Solid state memory (flash drives, sd cards, etc.) seem to be the best way to go. It's not bullet proof, things can still go wrong, but no scratches, it' more compact, more economical,etc.The makers I spoke with said that although it's intended use is not for long term storage,they assured me that the data should last atleast 100 years. Here's the rub, the fly in the ointment, the wrench in the works. Saving the data is only half of the problem, just ask the U.S. Navy. A Popular Science magazine article discribes the problems they had with reading schamatics aboard aircraft carriers do to the constantly changing software enviroments. When saving data, always use the most popular formats (jpeg,etc.). Also be careful of what programs you use to create the data. Certain photo editors and other programs create files that can only be opened with the same software. Did you ever try to watch a video clip and was told you need Quicktime,Flash player, etc.? I hope this information will be of some help to you.
Shelf Life Varies by type of media, manufacturer and when
by taphilo - 1/30/09 10:28 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
CD made between 1992 and 1996 that were burned were expected to last 10 to 20 years under normal storage.
Between 1996 and 2000 it went up a bit to around 30 years.
From 2000 to 2005 most went up to around 40
Sinec 2006 most have a top life of around 80 years.
Now, there are specs and there are manufacturing tolerances allowed with the specs - and the type of substrat and reflective material used.
Thus even some within spec could last 10 years less if they were on the low end, and on the high end of manufacturing tolerance they could last 20 years more.
Gold backing lasts longer than silver - reason they cost more. Also, the better the material the CD is made out of - more rigid, less permenable to oxygen eating into it as well as other airborn contaminates, the longer they will last.
Kept in cool place, not high humidity, even the cheap ones will last easily 40 years.
They do accelerated testing so no one really knows how long they will last. The older photo CDs that I have are from 1992 and they still read fine.
What is more worrisome is the changing of hardware - will the CD readers made 30 years from now still read the 8 different types of CDs / DVDs now in use?
Long, but not indefinite.
by Brock Tungsten - 1/30/09 10:35 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
Few of my disks have survived for more than a five years and I suspect that improper storage is the problem. I don't like air conditioning, so my apartment tends to be a bit warm in the summer. CD-R/RW and DVD-R/RW disks like an environment most people prefer -- temperature in the low seventies with low to moderate humidity. It is also important to protect them from prolonged exposure to artificial light and any exposure to sunlight. If you treat them with a modest amount of care you should see ten or fifteen years of service from them.
As for duplicating your back-ups on another medium, do it. The old saying, "don't put all of your eggs in one basket," is sound advice.
Shelf life
by johnisq - 1/30/09 10:55 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
I've been backing up myself since 1998 on CDs. Out of experience, only reliable (and expensive) brands withstand the test of time. Personally, I use TDK Gold media.
Obviously, avoid heat (particularly sunlight). I've read a web tip that claims that wrapping an old CD with aluminum foil for 2 minutes before using it improves its clarity. Unproven!
dvd and cd have shelf life if improperly store
by johnttlin - 1/30/09 11:09 PM In reply to: Do burned CDs and DVDs have a shelf life? by Lee Koo (ADMIN)
Yes cd and dvd have if you improper store the cd or dvd . enuff said
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