163 total posts
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Commercially-pressed CD's and CD-R or CD-RW disks are fundamentally different technologies, which is why a commercial CD will continue to be readable long after a CD-R has become unusable.
A CD drive uses a focused laser beam that is reflected from the media surface in the CD disc. The beam is reflected onto a sensor that detects changes in the amount of energy that is reflected. The original (commercial) process used perforated aluminum as the media surface. When you use the term "pressed" you are using an old vinyl record term, but the production process is pretty much the same. There is a "master" disk that is put into a press which is filled with polycarbonate. The master disk has little pins sticking up everywhere there is to be a hole in the aluminum. The disk is cooled, and liquid aluminum is spun onto it. This results in an aluminum layer with holes in it.
When the disc is played, the laser reflects strongly from the shiny aluminum or less strongly (or not at all) from the holes. The reflection/non-reflection is translated into the ones and zeros of the binary data stored on the disk.
Over time the aluminum can oxidize or there can be other changes in the plastic and other materials that make the disc unusable. These are long term effects and the ultimate statistical life of a commercial CD is often debated, without conclusion, by the experts.
The CD-R and CD-RW do not use an aluminum media surface. Instead, they use a dye. When the disc is written, a high-powered laser causes spots on the disk to turn dark (hence the term "burning"). When played back, the sensor in the player sees the difference in reflectivity of the dark and not-so-dark spots as the binary data.
Unfortunately, because the dye is a light-sensitive chemical, over time it will fade. This can happen from the heat of the reading laser, from ambient light, and from chemical degradation in the dye and support media.
CD-R/RW media is safe for backup, and for creating alternate media (copying music files to play in your car so that if they are damaged from heat or wear out you can make another one, and preserve your originals elsewhere), and similar purposes. However, they are not safe for archival storage because they are not stable enough for that purpose.
Side note: when burning CD's for use in a car, for best results get "music CD's" which are designed for that application, or slow your burning speed down to 12x or 16x to get a darker spot from your high speed burner. The car will read the disc more reliably.
Insofar as tape storage is concerned, tape is also not a good archival choice of media. It's generally better than CD-R, although I haven't seen any comparative studies.
Major data centers who use tape storage refresh the storage periodically. Their Tape Management System (TMS) remembers the date the tape was recorded, and will call it up to be copied periodically. The old tape is then erased and reused until it reaches end of life (sometimes a fixed usage or time interval, sometimes when the number of recoverable errors reaches a threshold) at which time it is scrapped.
The whole issue of long term archive is complex, and goes beyond media. For media, if a data center stored its files on a 9 track magnetic tape twenty years ago, how would it retrieve that data today (you cannot find working 9 track drives). What if it had used an early Magneto-Optical (MO) drive? Small businesses have trouble when their tape drive fails, and they can't buy another drive in that old format.
File formats are another problem. I have word processing documents that deceased family members created years ago. I no longer have word processing software that will import some of those formats. I can (sometimes) extract the raw text and then try to reformat it in a current program, but if I don't have a printed original I don't know how it was intended to be formatted.
The only archival format that has stood the test of time is paper.
Submitted by: Kevin G. of Dallas, TX
Well, Carl, that so-called expert sure has stirred the waters and a LOT of people are wondering about the same question. However, your friendly Federal Government has studied the problem even longer.
To be specific, the National Archives and Records Administration, in charge of all of the record archiving of the government, has no standard on media storage, and requested NIST, that's National Institute of Standards and Technology, to write a new standard on media durability.
If you never heard of NIST, you're not alone, as NIST is more of a background organization, but suffice to say, they're the ones who creates the standards, references, and accuracy tests for all industries, from DNA to Time accuracy (in fact, if NIST operates one of the Internet "clocks" you can calibrate your PC to). NIST DNA reference material improves forensic DNA test accuracy. NIST also invented closed captioning and many other technology, but enough about NIST.
A gentleman by the name of Fred Byers spent a whole year testing various media, and wrote a guide for NIST to librarians who need to archive information on how to care for optical media such as CD-R and DVD-R's and such. In the guide, he basically stated that with proper handling (store in low humidity, no scratching, stored vertically, etc.) a DVD-R should last 30 years with no fear of losing any information. However, that is NOT an absolute number as it is dependent on a LARGE NUMBER OF FACTORS, some of which in your control, and some not:
Factors that affect disc life expectancy include the following:
? type -- as recordable media is more durable than rewritable media ? manufacturing quality -- you get what you pay for ? condition of the disc before recording -- obvious ? quality of the disc recording -- garbage in, garbage out ? handling and maintenance -- scratches are bad for any discs ? environmental conditions -- humidity and temperature can warp disc, ruining the reflective layer in the media. light, esp. UV light can destroy the dye used in recordable media, etc.
Let us discuss each factor in a bit more detail
All types of media can be damaged through warpage (disc bending), scratches, and reflective layer breakdown due to oxygen leakage.
Recordable media, in addition, is susceptible to UV rays, which affects the dye used in the process.
Rewritable media, with phase-change recording, is even more susceptible to UV ray and temperature.
It is generally acknowledged that certain brands of media are better than others, and often the stuff on sale is not the stuff you may want to buy and keep around.
What you may not know is that there are only like 16 media manufacturers in the world. They make the media for all the brands that you see in the market, and some brands / factories are known to make high grade media (i.e. they tested best for maintaining data integrity, even when the media was subject to aging tests). While few independent labs did comprehensives tests, a test in Europe a while back for CD-R's revealed that Taiyo Yuden (Verbatim), Kodak (Kodak), and TDK (TDK) kept the most data intact.
Condition of the disc before recording
A disc should be brand new when used. While shelf live of a media is up to 5 years, why take chances? Buy them as you need tem.
Handling and maintenance
Scratches are bad for any discs, as it breaks open the substrate layer and allows air to tarnish the inside silver reflective layer inside.
Scratches also can make information on the media unreadable by interrupting the laser's path.
Environmental conditions -- humidity and temperature can warp the media, and exposure to UV light can destroy the dye used in CD-R's and DVD-R's.
Hope that answers your questions.
Submitted by: Kasey C. of San Francisco, CA
In the '80's, the CD was introduced in the market and portrayed as "THE" solution to the vinyl records.
The CD could be thrown in a mud pool, step on it, scratch it, nothing would harm he CD.
Now we all know that CD's has a lower lifetime as their vinyl counterparts and are more susceptible to errors than them. This is also true for the CD as a media to record software.
The early CD's, were recorded at maximum 640 MB. Mostly not even 640 MB but something like 528 MB. This made them less susceptible to scratches.
But as the CD technology was in a constant evolution, overburning a CD to 800 MB and more became common use. Also the DVD was introduced, offering 4/9GB on a wafer of the size of a CD.
It is obvious the the tracks are becoming so small that the finest scratch, the smallest fault, can ruin the CD/DVD forever.
Answering your question, there is no miracle solution to keep CD/DVD from deterioration trough age. But with a little bit of care, you can have many years of pleasure of your recordings.
1. Buy only CD/DVD from a good brand.
Buying low priced CD/DVD will mostly result in very disappointing experiences.
2. Don?t overburn a CD/DVD.
While the overburn technique is now widely accepted by most software, it is still not fully reliable and mostly don?t approved by the CD manufacturers.
3. Put every CD back in the jewel case after use, clean them as prescribed by the manufacturer, and avoid as much as possible touching the reading surface of the CD.
As a final remark, CD/DVD are nowadays not expensive and if you can make a backup of them, make a backup and store it in a safe place.
I use an external harddisk of 250GB (<300 CD's) to store a backup of the CD's/DVD's I have. Price of the harddisk is about 100$.
I have been able many times to rescue recordings which were otherwise lost forever by this harddisk.
Hope this helps,
Submitted by: Carlos
You have just discovered what most people don't discover until they actually lose data: commercial CDs and home-burned CDs are not the same. While a commercial premade CD will last a very long time if it is cared for properly, a home-burned CD will begin to deteriorate. The reason is that the home-burned version uses dyes to accomplish what the premade CD does by having it built into the disk. This is, of course, an oversimplified explanation, but it will suffice.
There are a few ways to maximize the amount of time a CD will last. First of all, buy good quality CDs to begin with. Stick with brand names that you are familiar with and have used successfully in the past.
Do not assume that just because a blank CD is made by a well-known company that it will be high quality.
Test them out by actually using them. One of the best ways to do this is to use them for your regular system backups. Be sure to actually restore from those backups periodically (easier if you have another computer handy that you can wipe out data on) or else use a backup program that allows you to mount the backup as a "virtual drive" and retrieve data from it.
This lets you know if there is a problem with a brand deteriorating unusually fast.
Second, never use labels on CDs. I found this out the hard way. Labels cause the CD to deteriorate much more rapidly than it otherwise would. Certain inks used in pens have been reported to do the same, but I have never encountered this problem, so it shouldn't be too severe. Do be certain, however, that you are gentle when marking CDs. Use a felt tip and do not press hard.
Third, put a note somewhere on the CD that tells you when you made it. This lets you monitor how long it has been since the CD was burned. If the data is irreplaceable, burn it to a new CD every 2 years.
As for the recommendation to use magnetic tapes, that has its own set of problems. Magnetic tapes also deteriorate, and they are subject to some damage that CDs are immune to, notably damage from electrical or magnetic fields.
In short, CDs are good for long term storage-- but don't assume that "long term" means forever. Check them regularly and burn them to new media when problems develop or even before if you can't replace what's on them.
As for storage, that is pretty much common sense. Keep the CDs in a case or an envelope if they are not actually being used. Avoid temperature extremes and handle gently. I also recommend making two copies of every important CD. This practice just saved my data when I discovered that the labels on my CDs had wiped out some irreplaceable family photos. It costs twice as much, but if the data is important to you then it isn't really very expensive, is it?
Submitted by: Denise R. of Lebanon, Missouri
Hi Carl N,
Your question has been set by a lot of people over the last 10 years. I've burned CD in 100s over the years and only found 2 discs with missing information. Lifetime of CDs is not limited due to one parameters only, more issues are setting the limit of lifetime. One is related conditions of storage and how you handle the discs. In other word, how careless or careful you are as the user. Then the material used in the CDs - how cheap a blank CD did you buy. And lastly your burning equipment, that is the laser diode.
When pressed CDs were introduced in beginning of the 80s lovers of vinyl records claimed, that CDs would last for 2 years only. But as you have experienced CDs from this period can still be played. I remember one report from about 1990, which claimed a lifetime of only 3-4 years. Looking into the report, it turned out that the condition of storage was -30C (some -25F) and reading/playing equipment had a worn laser diode. Most of us can only say: I don't store my CDs in the freezer and today?s laser diodes doesn't wear out as they used to.
Turning towards recordable CDs, the whole issue is a matter of having a whole bunch of clear holes placed in circles in a foil. Readability of these holes are depending on a number of issues. How clear are the holes? Is edge of the hole clear? Is the reflectivity of the materials sufficient? Is the laser still as effective as it was? or has the surface become matte? For the early CD-burners this was jeopardized by increasing burning speed and some blank CD had doubtful foil material. Adding, to this some CD-burners were even sold with writing speeds beyond its capability. Many blank CDs were rejected in this period due to bad burners rather than bad discs. It is my conclusion, that this interim period has given us some doubtful discs.
You have to be careful with your CDs and also a little bit extra careful with your own. They don't like heat, bright light, bending, and writing with aggressive writing pens is also nasty. Especially pens with unknown chemicals may etch the CDs, it is just like burning, but this time controlled by the chemicals.
In case you wanna increase the lifetime of your recordings, you may buy CDs which is claimed to 300+ years lifetime. These CDs are referred to as GOLD-CD. These CDs has a special layer which include some 24ct gold. The advantages of these CDs are the ability to create clear holes into it with reduced oxidation or corrosion over time. Amazing almost also unbelievable 300 year. Just 100 years could be great for me. In 10-20 years everything would be transferred to new media type anyway. I saw a report on the 300 years at
Price of these GOLD CDs is 10-20x times the usual ones.
You have been suggested to use magnetic tape. Nor tapes does not last forever. As matter of fact the sound quality decays over time; frequency range is decreased by each use. This loss you can not be restored as with a digital media. Only digital storage keeps its audio frequency range over time and use. Like R&R;DIGITAL media is here to stay. You may call it CD, DVD, MPx, Blu-ray or whatever, but it's digital.
I believe that today?s discs and equipment can provide a disc with sufficient lifetime for most of us and may even restore your more doubtful discs from the early burning time with success. Even discs which are registered as 'No disc' may be restored by copying it today. In case you wanna assure yourselves; let the PC verify the burned disc, this option is normally disabled by default.
What shall I do with my precious discs from the early days? My best recommendation would be to make a new copy, while the old is still readable. This is easy and cheap to most of us today as having two drives in your PC is not uncommon. Lastly, the quality and lifetime of recorded discs is today likely to most depended on your own care.
Submitted by: Leif M. of Helsingor, Denmark
Regarding problems developing over time with recordable CD-R media, I've run into some of this myself, but I also have quite a few discs that were made back when the very first 1x CD burners were made available to the public, and they still read just fine for me.
I suspect that there are several factors involved here.
1. I'm certain there's a difference in quality between brands of CD-R media. A number of my really old CD-Rs that still read flawlessly today were Kodak branded, and were considered expensive "premium quality" discs at the time. They're even physically a little bit thicker than most other media I've handled. By contrast, some of the generic media I purchased because of the low price on 100-pack spindles has actually developed "bubbles" where you can see the dye that's sandwiched between the layers of plastic is disintegrating. (Of course it won't read if small spots are completely gone!) There were/are several different types of dye used for CD-R media, as well, and I wouldn't be surprised if it's turning out that some types have better longevity than others. For example, Verbatim was known for using their trademark blue-tinted dye, while others were shades of green or gold.
2. From what I've read and observed, handling makes a big difference too. Leaving your CD-R's exposed to sunlight (as folks tend to do with music CDs used in their cars or trucks) probably shaves years off of their lifespan. Putting them in some type of jewel-case or sleeve when not in use is a very good idea. Boxes of empty jewel-cases can be purchased fairly inexpensively at most office supply and electronics chain stores.
3. A CD-R holding computer data is inherently more "fragile" and subject to data loss than a CD-R recorded as an audio disc. The standard used for recording audio CDs incorporates quite a bit of error correction information to handle small scuffs and scratches on the media, but besides that, audio data is spread out over a much larger portion of the CD-R. If you have a .ZIP file stored on a CD-R, for example, a pinhole-sized mark someplace on the disc where that .ZIP file is stored can easily be enough to prevent the whole archive from extracting properly. By contrast, the same sized mark might only cause a very brief "stutter" at one point of a song on a music disc (or not pose a discernable problem at all, due to the error correction).
If your audio discs are already deteriorating to the point where players are rejecting them as "unreadable" or they're skipping badly, it sounds to me like things have gotten pretty bad. The only recommendation I'd have is to re-record your music to fresh, good-quality CD-R media and throw out the old ones - and in the future, make a habit of transferring your music to fresh discs every few years or so.
Luckily, in the case of computer software backups, they tend to become so outdated, you no longer really need to keep them by the time the media they're recorded on starts failing. But for those trying to preserve digital photos and the like, I'd recommend this same procedure. Make a fresh set of backups every so often and discard the old media - before it fails on you and you lose something priceless!
Submitted by: Tom W.
CD burned media fails after time.
I am a practicing technician and this is not a new complaint. It is my firm belief that most consumers burn their media at the fastest speed possible for both their software and the media they use. This is fine but there may well be a trade-off in doing this.
What most consumers do not perhaps understand is that commercially produced CD's have actual pits pressed into them that represent the digital data of the original sound data. A burned CD on the other hand is made by fabricating a photo sensitive layer to mimic the pits found in pressed media.
I have found three major causes for this consumers problem they are as
1. A slower burn makes a stronger image representation in the photo
sensitive layer of a burned CD. A faster burn while successful may not impress the photo sensitive layer as effectively as a slow burn. Over time the burn fails as the photo sensitive layer deteriorates.
2. Sunlight and other forms of intense light can effect a burned CD
because it can cause a distortion in the burned media's photo sensitive layer.
3. Scratches by far are more evident on burned media and more easily
caused than on pressed media. Most consumers seem to ignore the manufactures warning and suggestions. Handling of the disc in a careful manner as advised by the manufacturer is the best policy here. I use a camera lens cloth to clean surface of all my media. A camera lens cloth will not scratch the disc surface. Paper and regular household cloths will cause scratches.
Observe the above and I do believe you will have better results.
One more thing always use the media recommended by the burner manufacturer. It is endorsed and guaranteed to work, many of the cheap non name discs out there are just not up to par. Its just like the old cassette tape days.
Most audiophiles went for tapes like Maxell, JVC, Sony etc. but as everyone knows there were a lot of bogus brands out there for the un-informed to purchase.
Submitted by: Peter K.
> I recently read an article by a data storage expert who claimed that
> burned CD-Rs and CD-RWs can be expected to last only two to five years
> and not a whole lot more. I personally have commercially pressed CDs
> from the 1980s that still play fine, but I have begun to notice that
> some of my burned CD-Rs are beginning to skip
you mention that there are basically two types of CDs: Those that are created with all information in place and those you can buy and write on.
The first type is quite robust as the information has been "engraved" into the surface just below the reflector. The most critical part of such a CD is the reflector, most often a very thin layer of aluminum.
The second type of CD works a bit differently: There is a dye layer below the reflector and the information is written onto the CD-R(W) by "burning"
and thereby locally changing the optical properties of the dye. The most critical part is the dye, besides the reflector as above. If the dye degrades the CD easily gets unreadable. The dye of CD-RW is even more critical as it must be "resetable" - another constraint.
> The expert suggests that for secure long-term storage, high -quality
> magnetic tape is the way to go.
This solution is quite expensive as you need a tape drive and enough tape cartridges, but has the advantage of a much larger storage capacity. If the manufacturers say their tape cartridges are reliable for a very long time they have one advantage above CD-R: This type of storage device has been around long enough to prove it. CD-R has been on the market for no more than 10 years.
The best strategy for the private user is: Have a good archive strategy, save often and store the media carefully in a dry, dark, cool place. If you store every file more than once you have a better chance to retrieve it.
There is no real alternatives to CD-R. Use high-quality ones. Do not use any DVD variety as their reliability is much less. DVD may be used for an image backup of your boot drive so you can restore your present configuration for the months to come.
Submitted by: Alexander V.
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. 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, In fact, there are 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, I think because few vendors use life span as a selling point.
I've had good luck with Verbatim media, and bad results with TDK. Playback with the TDK discs I used degraded steadily over time, in spite of very little use, and not much in the way of scratches or other blemishes on the disc. On the other hand, the Verbatim discs I've used have held up well over time, and under more use than the TDK ones I used.
Opinions vary on how to preserve data on digital storage media, such as optical CDs and DVDs. I have my own view: To overcome the preservation limitations of burnable CDs, I?m suggesting using magnetic tapes, which, as I read, can have a life span of 30 years to 100 years, depending on their quality. Even if magnetic tapes are also subject to degradation, they're still the superior storage media.
But I want to point out that no storage medium lasts forever and, consequently, consumers and business alike need to have a migration plan to new storage technologies.
A Good Question to get in this subject is Does Burning Speed makes difference in quality of CDs? Someone told me that the burning speed makes a difference in the quality of the records. The lower it is, the deeper it burns and therefore the better the quality is. I heard that there are some audio technicians decide to burn masters at 2x and copies at 4x due to getting digital noise from higher burn rates. Might just depend on the burner quality and the burning program...
Hoping you get the Point of my explanation.
Submitted by: Sameer T.
Everyone who owns a business is always trying to be enticed by the security and the longevity of magnetic tape. And although I'm apt to agree with them on its durability, I don't use it to back up important data in my business. I have two problems with magnetic tape vs. CD or DVD. The first problem is hardware. Data backed up on a CD or DVD can be loaded into any computer with a drive capable of handling the media. The same can be said about tape backup, however you are more likely to find a computer off the shelf with a compatible CD or DVD drive vs a magnetic tape drive. The other problem is the need for long term storage.
As a business owner, I'm backing up my important data every one to three days. I've been using CD-RW media to do this for years. If a disk gets corrupt, you can reformat it using your burning software, then use it again. If you are concerned about your CD becoming corrupt, simply burn two or three. The cost of three CD or even DVD media is much more reasonable than the cost of one of those tapes. And if my server dies, I can buy any computer at any store, and load the data onto the new computer right away and I'm back in the game. I have several people trying to convince me of the benefit of a paper backup system. I find it easier (and cheaper) to have multiple electronic backups. My business server has a RAID 1 card and two hard drives which mirror each other. I have the CD backup, and I then take this data and save it to a secure partition on another machine in a separate location.
The likelihood of all of these systems failing at one time is highly unlikely. And if it does, I'm taking the day off, because that's just real bad luck. As far as long term storage (like music), I've noticed that CD-RW can lose the data in the long haul, but haven't had any problems with CD-R media. I have some that skip, but not for a reason I didn't know about. I buy the large spools of CD-R which don't come with jewel cases. So these disks get abused. If you know you are going to keep something for a really long time, I would make sure the disks you buy have jewel cases. And you can apply the multiple disk system with this as well. The media is easy on the wallet, and the more backups you have, the lower the risk you will actually lose the data.
I don't think I answered all the questions, but that's my take.
Submitted by: Dave K.
I don't use CD-RWs, but I do know that the older Memorex discs (with the blue dye) lasted for me, about 4-5 years. They're all unreadable now. The interesting thing is, several of those CD-Rs were never played and were, litterally, kept in the dark all those years.
I pulled one out about a year ago noticed the label side was yellowing, so I tried to play it and forget it.
This only happened with the blue dyed discs.
I wrote Memorex complaining about this and those spineless people didn't reply to me at all.
My Kodak disc of about 8 years, is still playable.
can't they create extremely stable dyes
it seems that that optical drives cd and dvd -/+
were being pushed as the the best best way to archive
data and pictures , videos and the the like, well they do work to a degree- a small degree. I have bought lots of 100 cd-r,dvd-r etc and i am very lucky to get maybe 1 out of 10 to record any data. O.K. why cant they create extremely stable dyes to last at least 10 years. these scientists are suppose to be top of the line. I'm tired of wasting money for cds and dvds that can't even make good mixed drink coasters
try a different recorder
If you're seriously having that much trouble (90% failure rate you indicate) you've probably got somethign wrong with your burner. Some brands of cd's work better with some brands of burners. I've never really had much trouble with this, with an exception of an older burner I used for a while (it was a 12x10x?x plextor drive). Most newer drives I've been around don't bother with this.
On a side note, I have purchased hundreds of spindles of cds for personal and business use over the years and come across an old (probably 3-4 years) spindle of disks a month or so ago, and found they are not real reliable for writing, this would make one believe if I still had cds that were written 3-4 years ago I may have the same trouble reading them.
Up to this point I've never had much trouble reading disks except for those that get scratched.
One thing I've noticed on car audio players, I've burnt new audio disks, played them maybe a month and they start to skip. I think this was because they were cheap disks though.
Was your car hot?
I noted your comment about shorter life of CDs in your car. Could it be that the temperature there was higher than was good for storage of CDs?
What is an acceptable temperature for storage?
I'm sure it gets melts hot in my car during the summer. I guess I'm not really sure what an acceptable temperature is. What it seems like I really noticed, is the more I played the disk he worse it got.
What is an acceptable temperature for storage?
Certainly not "melt hot" - as far as I know temperate temperatures are recommended not tropical ones. And maybe it's even hotter in the player than in the body of the car.
I kept everything important on floppies until 2000. Then I transferred everything to Memorex CD's. I had nothing but problems with their magnetic media so I can't explain what possessed me.
A year later, only about half were readable. None can be read now.
I've never had a failure with TDK, Philips, or Verbatim that couldn't be attributed to a drive problem. By that I mean that I had a TDK drive that seemed to prefer TDK disks. The Philips drive liked Philips or Verbatim, but I had a couple of bad burns with TDK.
Now I have a LG drive and it doesn't seem to care.
Stability of Recordable Media
I have been in computing since the 60s and have seen all forms of recordable media starting with punched cards/paper tape. For them and all media since their reliability has always been dependent primarily upon:
1 - Quality of the recorder
2 - Quality of the media
3 - Quality of the handling
4 - Quality of the storage environment
I have floppy disks that are well over 20 years old that show no signs of deterioration as well as one hard drive in that age bracket. I have yet to lose a CD/DVD due to scratching or other deterioration.
I sometimes run into a cranky CD or DVD when recording and I immediately discard it. I have not had any problems with RW media but do not use it for long term storage which I define as more than 1-year.
The moral...pay for quality and treat your media like you treat your mother's fine china...carefully and respectfully.
Other advice from our members
CD-R's and RW's do have a lot shorter lifetime than commercially pressed CDs. The way I keep most of my CD-R's is to keep two copies of them, use one as the main copy and the other one keep seperatly in a safe location, then when the main copy goes, backup the backup and start using the backup (that way your not keeping a really old version).
There are some burnable CD's that are of a higher quality than others, there are some things to notice when buying CD-R's. Firstly check the colour of the dye, they come in a variety of colours and some colours are much longer lasting than others, I think the gold coloured dye is the best, but likewise is also far more expensive. Then another thing to check is the top of the disc. Branded discs can be a bit of a nuisance for printing/labelling but quite a few branded discs have far better tops than others. TuffDisc have a very good protection system on the top of their discs and do last quite a bit longer. Unbranded discs usually just have the following sandwiched together - the plastic disc, the dye layer, and then the reflective coating (usually aluminum foil), however some CD-R's also have additional paint layers which protect the aluminum foil area getting scratched. Of course if all this protection fails and you still end up with discs with information no longer accessible one of your best options is to try various CD recovery tools such as BlindWrite and Alcohol 200%, these programs will allow you to recover most data and burn it to a new disc.
Submitted by: Darren F.
As is often the case when a form of media comes out, people are quick to jump on all the "new and fun" things connected with it. Like CD labels.
Not a good plan. It's just a scam by the manufacturers to 1: sell you more items. and 2: make the discs unreadable in a shorter time so you have to buy More discs and reburn. They don't care that you may lose important material that can't be replaced, like digital pictures.
I've found one way to make the burned cd's last longer, is to used ReReadables instead of Readables and NOT to put a commercial CD label on them. Stick to the plain old felt-tip marker and put the labels on a cd case cover. I number code mine to make sure they don't get confused.
It's sad that even with the multi-billion dollar industry they have going, the cd makers still have to rig the whole process to make even More for them selves.
I learned the hard way, by losing discs with digital pictures of trips to New Zealand on them. Not to mention dozens of rerecorded songs from my own music cd's ( to mix my own cd's) as well as valuable backups for computer programs. You buy a program online, download it and burn yourself backup, only to lose the whole program when the media fails. Been there....done that...not happy about it!
While no source of media lasts "forever" it would be nice if one of the media companies came out with one that would, at least, out live the original. Isn't that why we "back up" things? To protect against "loss" ?
Submitted by: putergoddess
I have been a big fan of backing up data, but starting around last year a burned CD that had some old family and friends pictures was not reading in any of my cd drives. I have just recently purchased something that will take all my data off of CDs and DVDs and put it on a home network storage device. Many of the companies like Netgear, Belkin, Linksys, and many more have moved to the realm of affordable home network storage. It can move all your data off of optical disks, like CDs and DVDs, and onto hard drives. The majority of the devices allow for upgrading to bigger sizes of hard drives with either USB drives or IDE drives. Also some of the devices can be configured for FTP so that you can be anywhere with a high speed connection and you can pull information off of your home storage device. Personally I believe the home network storage devices will start to take the place of CDs and DVDs in the next two to three years because of more reliablity and eases of getting to your older data.
Submitted by: Blair of Las Vegas, NV
i personaly dispize optical discs just because of the extreme sensitivety to scratches. and CD/DVD rot is a fairly large problem...some of them last a verry long time...but alot start to get pinholes/strange marks/coffie like stains on them. it happens from the alluminum/gold layers in the discs corroding over time, well made discs should be fine but if thers any impurities in the metal or if any minute amont of air gets in ,ether in the manufactureing process or from a lable side scratch (CD) or if the two thin plastic discs (DVD) become unglued/delaminate or if the seal is broken from being bent/dropped, than the air/dirt gets inand starts to slowly eat away at the metal.
i personaly think that xtra hard drives, ZIP disks or HQ tape as mentioned are the best choise for long term data storage.
i have had several of my commercialy bought CDs rot and get full of pinholes , even thought i allways took good care of them, some of the ones that are suffering from it are only like 6YO...i havent had much troble with CD-Rs (with the rot issue anyway), but i only started burning CDs about 3 years ago and moast of the ones iv burned for data back up iv just thrown away because the data i backed up had changed or wasent needed anymore, they still allways seem to get scratched too. CD-RWs on the other hand...i bought a 5pk of memorex ones about a year ago...all of them are now useless and develped pinholes and wouldent hold data relibly. the last one i went to use about 3 months ago , wich was still in the shrink wrap, was full of pinholes right out of the shrinkwrap.
DVD-Rs and DVD-RWs i dont know because i just started using them about 6 months ago,and i only own 2 pressed DVDs wich are only about 6months old now, they still get scratched but i havent had any rot problems yet with them, but like i sed they are all fairly new and havent had time for it to set in yet.
we have casssettes from the 70s and VHS from the erly 80s that look and play fine, hard disks and zip disks...magnetic is the way to go IMO.
Submitted by: CathodeRay Tube
DVD RAM is THE way to go in particular for long term data storage, not CDs.
They last 100 years, and have superior recording features:
-It is the only DVD disc format that uses Random Access Memory (read, write) technology. Random Access memory allows you to watch the beginning of a recording while the DVD recorder is still recording the end of the program.
-DVD-RAM media formatted for PC can be reformatted for use with a stand-alone DVD recorder.
-Unlike DVD RW and R (+/-) formats, DVD-RAM does not have to be "finalized"
and can be erased and re-recorded, and it can re-record 100 MORE times than DVD RW discs can be. DVD RW discs will more and more lose future recordable space the more they are re-recorded. In comparison, DVD-RAM discs can be re-recorded up to 100,000 times without ANY decreased record times.
-Unlike the other formats, with DVD-RAM, you can't "accidentally" record over something.
Please view the numerous posts made about it that were answered in the Q & A dated 1/20/06 Demystifying those confusing DVD formats:
They cover links about which players, players/recorders, and computer DVD drives support and/or record to DVD RAM media.
Submitted by: Dierdre W.
Be ware of men bringing doom and gloom. Expert huh? Ask yourself this, what are the high quality audio cassettes made of? What are the high quality Beta Max made of? What are the high quality S-vhs made of? Thats right, high quality magnetic tape. If you have a audio CD that you want to last forever, sorry, it aint happenin. Nothing lasts forever. You can however make it last for almost forever by making a copy of that brand new CD you just bought, ( it's legal to make a backup) and put it away in your desk drawer and play the copy. Same thing is true for DVD's, just make a copy and use the copy till it gets trashed and get out the original and make another backup. As long as you put the original in a dry dark secure place in its container it should last a very long time.
There a few free download programs that you can rip your CD's and DVD's (again legal)
and extend the original quality.
Submitted by: Nathan
From what I can understand, both CDs and DVDs can be permanent, providing they are handled correctly. One should only handle via the edges or the hole in the center and it's been found that fingerprints can actually do as much damage as marks or scratches. Also they should not be exposed to extremes of heat or cold and kept out of direct sunlight. I store mine in their cases immediately use and never leave they lying around.
I don't know whether this is right or not, but I read that if they do get marks on them, they should never be cleaned in a circular motion, but in a straight line from the center outwards with a clean cotton cloth.
I know one can get sticky labels, but I was advised by a store assistant not to use them, but to use DVD/CD marker pens (on the label side only and never on the read side). And finally, for stubborn stains (that should not be there in the first place!) CD/DVD cleaning fluid can be used (alcohol based).
I sincerely hope my DVD-Rs have a long life as I've spent hours transferring from old videos that are deteriorating now... I guess only time will tell. My philosophy is to "treat them like gold"...
Submitted by: Derek A.
CD-R Life and Storage
Carl, it sounds like it is mainly music CD-Rs you want to archive. You don't say whether you want exact copies, or whether you are using a compressed format like MP3. Whichever it may be, and this may seem a somewhat alternative answer, but I would suggest you investigate MiniDisc. To summarise the main advantages:
New minidisk media is currently available at under a dollar a disc, with a guaranteed 50 years archival life.
Years of minidisc testing has revealed no sound or surface degradation after thousands of playings.
You have the advantage of complete re-recording flexibility: all tracks can be erased, moved and/or replaced any time with out affecting your disk.
The minidisc compression system (ATRAC) is much less severe than MP3 and results in a far better sound, which can truly be called "CD quality". Even if you did not wish to compress your CD arrchives, you will need very high end audio equipment indeed to detect any sound difference.
Cons? Well I guess MiniDisc may be called an obsolescent system, but no more so than the still 'standard' 74 minute CD disc we've had since the 80s, which is rapidly being replaced by music downloads and hard drive or flash memory storage. And all but the more recent CD players won't play the new storage compression and media formats.
Submitted by: Peter K.
I have had some problems with skipping and also found that strange noises have appeared. The answer to this problem is to use a disc cleaner that can re-surface the disc. This item can be bought as most good retail stores such as PC WORLD,CURRYS, OR from internet shopping channels.
I for my usage bought mine from http://www.max.tv The cost was
Skipping CDs can be saved by washing with liquid soap
When a burned CD starts to skip (less than 5% of mine have), I wash them with warm (not hot) water, a soft (Bounty) paper towel, and liquid dishwasher soap (Joy). I soap the wet towel and then wipe it in a radius (NOT circular) fashion across the backside of the disc, normally twice around. Then rinse and air dry in a rack for at least a few hours (wiping CD dry might hasten other damage - don't know)
I would be interested in comments as to what pen to use to write label on the other, colored, side. I now use only a black Sharpie. My CD-Rs are from Maxell.
Cleaning discs, pressed or burned.
I developed this method over a period of time, and have shown others, who have found it equally successful.
1. Run the kitchen tap to the hottest water your fingers can handle, and reduce to a gentle stream.
2. Pour dishwashing liquid directly onto the data-side of the disc.
3. Holding the disc by a finger through the spindle hole, use a wet finger to gently spread the dish soap around the entire disc. This should be thick and act almost as a lubricant for your finger. Obviously if the disc has grit on it, rinse first.
4. Hold the disc under the tap flow so that the water rinses the soap directly from the surface of the disc. If the disc is undamaged, the water will leave the disc completely clean and dry. If small drops persist, then either the water is not hot enough, or the disc is damaged at the point where the droplets remain. Rotate the disc gradually around the finger that is holding it until all the surface has been rinsed clean.
The only drying that should be required is a few drops of water adhering to the edge of the disc--there should be absolutely no need to touch the data surface, and of course, you remembered to put a plug in the sink so that you could use that soapy water for normal washing up, didn't you?
Now that DVDs are commonplace, and VHS dying fast, I have successfully recovered previously unplayable rental discs using this method, those that still won't play are generally so badly scratched that they need recovery grinding which can only be done once or twice, so let's hope the next generation of discs are made of a hardier material.
Tap water a no, no?
Our area has extremely hard water. There is no way that I'm going to wash a disc with that stuff. I have a bottle of CD/DVD alcohol based cleaning fluid that seems to work on discs that aren't too dirty. Netflix advises their customers to use Windex and to gently wipe from the center hole to the edge. Some of the rented DVDs I've seen have been extremely dirty and scratched and still worked. In any case, once a disc is in bad shape it needs to be backed up before it's unreadable. My first CD player used a cassette system. Discs stored in those cassettes still work, but the software (for DOS and Win 3.1) is outdated. I suspect that our CDs and DVDs will last longer than the hardware to use them on.
I Clean CD's by wiping them with a cloth and alcohol. Factory stamped CD's don't dissolve in alcohol. I don't know about CDR's, and there's alot of different substrates around.
Alcohol can be damaging to certain plastics. They can dry oils within the plastics making them brittle. I don't know what type of plastics are used in cd's and dvd's, but if they are like polycarbonates, they can be damaged. I have had this happen to motorcycle windshields over some years.
What difference does it make if the CD disintegrates in 10 years or in 1000 years? We don't really buy computers, we "rent" them until they suffer a final failure or for four years, whichever comes first. Commonly available media today did not exist ten years ago, and modern computers are unable to access media that was in common use 30 years ago. Can you read your 8" and 5" floppy disks? What about the audio cassette tapes from your VIC-20, Sinclair, or TRS-80? The microcassettes from your HP-41? ROM's from your HP-41 and HP-71? Yet, photographic negatives of Abraham Lincoln are still around and are still printable and ink-on-paper or ink-on-animal skin documents are around that are much older. And cuneform clay tablets are around that go WAY back. Possibly the greatest threat to information is repeated redacting that some documents like the bible suffer at the hands of censors and politically correct tyrants.
In the long run, the sun will become a red supergiant and engulf the orbits of all the planets out to mars, and nobody will ever know that we were here. Whatever storage medium we use best be on Jupiter or beyond.
As for storage defects, there is a whole branch of computer science called "fault tolerant computing" wherein we study error detecting and error correcting codes. The consequece is that a cleverly encoded body of data can be restored to perfection if it is not excessively corrupted. This all becomes a probability game where you pay for improved reliability with extra redundant bits. There is no reason CD's need to be susceptible to scratches.
I once tried to clean a CD with acetone. It had some kind of adhesive, probably rubber cement, on it. The result was not good. However, polycarbonate plastic is wonderful stuff and has lots of uses. It withstands most chemical attack, it is easily formed at high temperature, and easily cut or machined.
RE: WHO CARES?
IN ESSENCE, YOU ARE RIGHT, WE ONLY RENT PCs A BIT LIKE CARS REALLY, THEY ARE ONLY TRANSIENT MATERIAL OBJECTS THAT WE BUY AND DISCARD AS MORE RELIABLE/CHEAPER/ETC, ETC, ETC, THINGS COME ALONG.
I SUPPOSE WE LIKE TO THINK THAT OUR WRITINGS, PHOTO'S E.T.C ARE THERE FOR POSTERITY, AS THERE MAY BE SOME GOLD AMONGST THE DROSS THAT WE SAVE IS AVAILABLE TO WHATEVER FUTURE GENERATIONS.
MIND YOU, HAVING STATED THE ABOVE, WHAT IS THE POINT OF LOOKING FOR THESE ALLEGED BITS OF GOLD? IF HISTORY TEACHES US ANYTHING, WE LEARN NOTHING FROM IT! WE STILL HAVE WARS, RELIGIOUS BIGOTRY, HUGE UNSUSTAINABLE POPULATION GROWTH, GREED, CORRUPT POLITICIANS, ETC, ETC, ETC! SO MAYBE YOU ARE RIGHT, WHY BOTHER TO SAVE ANY KNOWLEDGE EXPERIENCE ETC, WHAT GOOD WILL IT DO?
HAVE A RELATIVELY PEACFUL NEW YEAR.
Cleaning/restoring problem CDs
I am a computer technician. I work out of my home and average 60 service calls each month, mostly to people's homes. I have been asked to reload software from failed CDs with a host of problems. Dried cookie crumbs and finger prints from little hands to nasty scratches.
Here is what I do. As in another post, I wash with warm water and liquid handsoap. Never work in a concentric fashion, always a radial, from the center to the edge, not around the disk. Scratches that are parallel to the burned rings are more difficult to read around than scratches which run across the data area. I dry with a soft hand towel. But what about when washing is not enough.
I searched for a polishing compound which would not destroy the clarity of the plastic surface. I tried various things on coastered CDs and found only one thing that fit the bill. I don't know if brand names are taboo here so I will let the moderators decide. I am not trying to plug a brand but my solution ended being very brand specific. Toothpaste was the answer, specifically ''Glister'' toothpaste. Turns out everything else I tried marred the clear plastic surface. Glister was able to diminish/fill/? scratches that nothing else I tried could do. I use it after washing with soap but apply it the same way. I just keep swirling it with my finger on the disk surface like waxing a car. Rinse with warm water. I dry CDs with a soft hand towel. I now carry a tube in my onsite bag everywhere I go. There are some gouges that I cannot fix. I have not delved into acrylic fillers, etc.
Good luck with whatever CD problems are yours and I hope maybe this might help you.
With regards to HD backup vs. cd/dvd-
I see that some members are recommending a move to hard drive backups instead of cd/dvds. I agree, sort of. A warning should be issued that although the cost of very large hard drives, external and internal, are dropping like autumn leaves, people need to remember the fragility of this media storage device. I, myself, was excited at that prospect of an archive, easily accessible file formats, and large enough to contain full collections of different media ? In my case, years and years of photos and family video/audio. I got a 200GB external drive for Christmas and lost sleep for nearly two weeks as I excitedly archived every photo I owned on two pcs and several cd spools. Then one morning as I sat to finish sorting folders prior to DVD backup, I accidentally pulled a cord with my foot, knocking the external drive over. It fell about 2.5? off the desk and hasn?t been recognized by a computer since. I am faced with difficult disk reconstruction and data recovery for thousands of $$ and will have to wait until the family photos are high enough on the priority list to divert grocery money to the cause. My point, of course is, larger hard disks, while attractive for a few reasons, are by far a more fragile basket to place your eggs. Maybe a dvd backup, or two, of the hard disk backup. If those files are really important to you. Caution is key. Best of luck finding somthing that will safeguard important data!
If a decade is OK, then that's enough for backup?
Quality Magnetic Media will also have life limit, do you agree? How long a time span will be considered long enough? Go to another side, how can we tackle, at last such situation: "all important data" has the need to be "kept eternally"?
Recently I have changed my mind in considering keeping what. There is a rule of thumb: if something had not gone into my sight for more than six month, and there is nothing change in my life, or more specificly, no any step back in terms of quality of life and living standard, etc; then it was something I can throw away. Maybe six-months is two short for other things. However whatever standards were set by us.
Hopefully you will read to this word, and accept my apologies for bad English.
I wonder if Barry W. has any information on this medium. Is the recording method similar or the same? Panasonic claim a very large number of re-writes per disk...
DVD-R/+R, DVD-ROM longevity. Blu-Ray and HD-DVD?
Is the info Barry W. presented for CD-R/RWs good for DVD media?
There is an enormous amount of DVD media in the market- not to mention the different formats!
Some of those discs are almost useless, of very low quality...
What are the guidelines for purchasing DVD media that will last longer?
Also, can anyone tell what the newer discs will bring in terms of longevity (Blu-Ray, HD-DVD)?
Blu-Ray and HD DVD
According to an article from CD Freaks, Blu-Ray discs are quite prone to damage from scratches.
The disc structure of Blu-Rays is quite different from present DVDs since its writing layer is much closer to surface. There is mention of specific manufacturing guidelines to sidestep this and other hardware challenges.
I wonder what this means in terms of longevity...
Holographic Versatile Disc
I think I will just skip the Blu-Ray and HD DVD entirely in favor of the Holographic Versatile Disk which is perhaps in a position to beat them both to market anyway later this year. The HVD format will initially have a 200 to 300 Gig capacity and a recording speed of 20 MBps. But it will eventually work it's way up to 1.0 to 1.6TB per disk - and that's uncompressed capacity - with a 120MBps up to 1Gbps bandwidth in a few years. Right now the designer, InPhase Technologies, is stating a data archive life of 50 years will be typical. With that capacity and longevity I'll be able to back up my whole network very easily and the backups will live longer than me which works out perfectly.
im still hoping D-VHS will catch on and become refined more...
even if the HVDs can store 1.6TB...please correct me if im wrong but,its still an optical disc..and as far as i know...im pretty shur it will have the same scratch/rot problems that every CD,DVD and LazerDisc befor it had.
Holographic versatile disks
DVD Ram Is like burning to a hard Drive
DVD RAM is an older format, but really good for backups, for copying and saving removable files.
Hospital equipment, as well as stand-alone digital copy equipment. (VCR copiers, good Camcorders, Exc., use them.) Unlike DVD RW disks, said to be good for 1,000 burns, these are said to be reburnable 100,000 times and have a useful life of 30+ years.
Basically there are 4 types currently available.
Type 1, Type 2, and Type 4 are cartridge style, while type 3 is a single disk like dvd RW. Type 1 are single sided and non-removable from the cartridge. Types 4 are double sided. (9.4 gig) Type 2, and 4 can be removed from the cartridge.
They Have 9 internal recording surfaces, while DVD R and RW have 3, so there is much better ECC error correction.
They can retrieve data much faster than DVD+/-R (22.16 Mbps), and as the name implies, they are random access. I put a DVD-triple format rewritable drive in my pc, windows loaded the UDF drivers automatically, and I just access it with windows explorer, (No burning software required).
The gold alloy on the recording surface was made specifically for computer use, DVD-RAM also have a scratch resistant surface.
I am currently paying about $2.00 for type 3 disks, and it's like using a 4.7 gig floppy. I'm thinking about trying to load, and run dos just from the disk.
The new triple format DVD writers will take type 2,3, and 4 and the mini type 3, and DVD+/-R, and RW as well as CD-R/RW. But, the next big change is coming real soon, HD-DVD.
The 'New' DVD-RAM can be written to hundreds of times.
Mind you they are still relitivly expencive as Optical media comes, but if you need a disk which needs to be written to repeatedly. Then yes, they work really well. Although you will need A drive that is DVD-RAM capable. LG makes a good one for about $100 The GSA-4160B is a Super-multi drive. which means I can write to vertualy any recordable media, Except Blu-ray.
Re-How long will CDs last?
It seems that the discussion about CDs is relating only to music. Is that correct? I would like to know how long photos last when burned on CDs.
Re-How long will CDs last?
hi, i`ve burned my photos on Memorex cd-r and after 2 years the photos are gone. it`s like an empty cd-r. the same thing is for mp3.
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