NIST Releases Study Of CD/DVD Longevity 325
dirkin writes "The National Institute of Standards and Technology has released a preliminary study of the potential lifespan of CD-Rs and DVD-Rs. The PDF study is here. A good starting point for deciding what type of media to purchase to keep those backups and photos kicking around longer. (You DID buy the silver/gold alloy phthalocyanine CDs, didn't you?)"
mobile fidelity... (Score:5, Interesting)
Re:mobile fidelity... (Score:5, Interesting)
Re:mobile fidelity... (Score:3, Informative)
Holographic storage (Score:2, Funny)
Re:Holographic storage (Score:2)
Re:Holographic storage (Score:3, Funny)
Re:Holographic storage (Score:4, Insightful)
However, the same doesn't apply for everyone. Many information-intensive companies are constantly struggling to keep up with the latest technology, spending big $$ on data retrieval. Thousands of tape backups aren't quite as easy to read and consolidate as a bunch of personal CDs. I guess the story here is that most people think CDs are a permanent storage medium.
I've not seen the silver/gold (Score:4, Interesting)
No, I've not ever ran across them, and it's not like they print the reflective layer and dye compositions on the side of the package. Mine are always green-ish.
(fp?)
Re:I've not seen the silver/gold (Score:3, Informative)
page 24+ has some info on the different dyes and reflective layers.
Re:I've not seen the silver/gold (Score:5, Informative)
Kodak Gold Ulitma CD's were a silver / gold alloy. I've still got a few from my first burner... they're 5 years old now and still (apparently) ok.
Here's a FAQ [kodak.com] about data life of kodak CD's. Accelerated aging at 80 degrees C and 80% RH seems a bit tough
Re:I've not seen the silver/gold (Score:3, Informative)
http://www.cdmediaworld.com/hardware/cdrom/cd_dye . shtml
see also the WSJ article, in PDF form
http://www.mitsuicdr.com/technology/WSJ.com%20-%20 Portals.pdf
Note (in the "well, duh" dept): if you google [google.com] or froogle [google.com] for phthalocyanine cd, you can find plenty of sources, since these are advertising points.... [Now including convenient links]
VHS tapes have quality grades too (Score:4, Insightful)
with CD-R media i have heard some claims that the black ones are good (look like a playstation game) if they will go to people that have a tendency to leave disks all over their desk... the black plastic lens keeps harmful light off the media surface.
test brands yourself... leave a few on your dashboard through the summer and see what the sun and temperature swings do to them.
Re:VHS tapes have quality grades too (Score:2)
Re:VHS tapes have quality grades too (Score:4, Insightful)
Re:I've not seen the silver/gold (Score:5, Informative)
From the CD-Recordable FAQ [cdrfaq.org]:
"Two components that many users of these programs always take as gospel are Media Manufacturer and Dye Data. These two readings are next to worthless.
The reason for this is that many CD-R manufacturers (like CD- Recordable.com) purchase their stampers (the nickel die that all CD-R substrates are molded from) from 3rd party sources. These 3rd party sources (either other disc manufacturers, or mastering houses) encode the data that these 'Identification' programs read, at the time that the original glass master is encoded. The 'Manufacturer' information that is encoded is usually the name of the company that made the master. Since stampers made from that master will be sold to disc manufacturers the world over, all of discs that those manufacturers produce from those stampers will contain the same 'Manufacturer' information. Information which is obviously quite erroneous and irrelevant. Very seldom will the 'manufacturer' information encoded on a CD-R actually tell you anything other than who made the original master. [...]
The second piece of data (the dye type) is also dubious. Because most master/stamper configurations are designed to be matched to specific dye types (Phthalocyanine, Cyanine, Azo, Etc), the 'Dye' information that is encoded when the master is produced indicates the type of dye that the master was designed for. This of course, does not assure that the manufacturer that buys and uses this stamper will be using it with the dye that it has been designed for. It is quite possible that a stamper/dye combination is used by a CD-R manufacturer that contradicts the 'dye' information encoded on the master. Therefore that information becomes as potentially misleading as the 'Manufacturer' data discussed earlier."
The only reliable piece of information in the "ATIP" region is the disc length. See section (2-38) for further remarks."
-- Joe
HD (Score:5, Funny)
Re:HD (Score:5, Insightful)
Re:HD (Score:2)
Re:HD (Score:3, Funny)
Ohh! Better check on it now.
Re:HD (Score:2, Funny)
Re:HD (Score:2)
The way of disks (Score:2)
Re:HD (Score:5, Insightful)
I have a 133 megabyte full height 5.25 Maxtor that is 20 years old, and a 44 megabyte miniscribe that is 22 years old. I saved them back from the days when they were GOLD to me.
Like a moron, I traded a 100mhz dual trace Tektronix scope for the 133 meg drive. Now it sits on the floor in the closet. But guess what?
The drive STILL boots and runs. Yep, it's loaded with IBM DOS 3.1 and I can still play some of my old Sierra games on it.
It's worth squat. But after 20 years of banging around on the floor as I moved several times, it still boots and runs.
I can't say that for CDR's I burned two years ago. Most of them over 2 years old are riddled with holes, like moths eating wool..
I DO NOT trust CD or DVD media for long term storage. Piss poor media if you ask me. I wish they had never invented the damn things, I put lots of important data on them over the years just to go back later and find it ruined and gone forever.
CD and DVD is a BAD technology. It's time to abandon it and reinvent the wheel..
Re:HD (Score:3, Informative)
You must have missed the point of the article. They aren't all created equal. Some discs will last a lot longer than others.
You can't create a technology that's immune from crappy generic products at the bottom of the price range, particularly a media technology. Buy better stuff.
Re:HD (Score:2)
Re:HD (Score:3, Interesting)
Doing the figures, HDDs aren't really that expensive compared to other media especially when you factor in the performance, reliability, stability and convenience. Buy one or two 200GB HDDs, backup everything (two or more copies just to be sure
The stability of data on magnetic disks is pretty good. The only problem usually is the electronics failing or the
Re:HD (Score:4, Insightful)
They may not be great for home backups (they never really were) but tape is definitly NOT a con-job. LTO-3 is 800GB per ~$150 tape, disk can't touch that, and they backup at up to 160MB/s, again a single drive can't touch that. The only reasonable solutions to backing up LOTS of data are tape or farms and farms of drives which are offsite with a VERY high speed network connection and which are write protected while not being backed up to. The latter can be done but it generally makes tape look cheap. Again for home use there probably isn't a lot of use for tape (I backup my machine by HDD as well), but for my clients I can't imagine using anything other than tape as an offsite/archival solution.
Re:HD (Score:2, Insightful)
JON
remember kids, (Score:5, Funny)
I Use Stone Tablets (Score:5, Funny)
Data loss (Score:3, Funny)
Yeah, right. Didn't you see Raiders of the Lost Ark? The Ark was full of dust.
At least you'll be able to melt some Nazis though.
Re:I Use Stone Tablets (Score:3, Funny)
Re:I Use Stone Tablets (Score:2)
Re:I Use Stone Tablets (Score:3, Funny)
They were documented in the EULA, tablet 251, paragraph 2, subparagraphs 2-7. Also see Appendix of Glyphs.
Stone is overrated as a medium (Score:5, Insightful)
Re:Stone is overrated as a medium (Score:3, Interesting)
Slashcode bug: you apparently copied that text from a page that used Microsoft Latin1 encoding, aka CP1252 [microsoft.com]. This allows you to represent the EM dash with 0x97. That shouldn't actually work, since Slashdot advertises its pages as using the ISO version of Latin1, 8859-1, which doesn't use that value. Ironic a
Re:I Use Stone Tablets (Score:2)
I carve all my important data on stone tablets. If it was good enough for Yaweh, they by Him, its good enough for me!
Unfortunately, stone can be very brittle and stone tablets shatter easily. You do know there were originally 15 Commandments, don't you?
Re:I Use Stone Tablets (Score:2)
My favourite scene, Moses parting the Red Sea
Data Corruption (Score:4, Funny)
Re:Data Corruption (Score:3, Informative)
phthalocyanine shmithalocyanine (Score:5, Funny)
It only becomes a problem if you're a big nacho fan...
Re:phthalocyanine shmithalocyanine (Score:2)
But if they make corn DVDs, we will then have pr0n on corn.
Re:phthalocyanine shmithalocyanine (Score:3, Funny)
Get with the times, man. It's called a cr0n collection.
Re:phthalocyanine shmithalocyanine (Score:2)
Actually, it has: http://www.ifla.org/IV/ifla64/095-114e.htm [ifla.org].
Does anybody know of widely available long lasting (Score:2)
Re:Does anybody know of widely available long last (Score:5, Informative)
Gold CDs don't last so long either (Score:3, Informative)
Gold CDs (Score:2)
This is important info! (Score:2, Funny)
i always knew... (Score:5, Interesting)
Still lacking "archival" information... (Score:4, Insightful)
Re:Still lacking "archival" information... (Score:3, Informative)
I design a certain type of reliability test equipment for a living. The tests performed by NIST are not standard length, they took much longer than industry standards for determining reliability.
The shortest test was 450 hours, most reliability testing takes around one week, NIST took at least twice as long for their tests, and up to two months for some tests.
Occasionally researchers will run longer tests (one ran a two year test on our equipment), but companies need information quickly.
Bottom line: the
Re:Still lacking "archival" information... (Score:3, Insightful)
I'm questioning its utility. What does it mean in practical terms? Given that I'm not going to be blasting a halogen light at my media, how long am I realistically expecting it to last?
Can't Stress That Fact Enough (Score:3, Insightful)
From the article:
Do not be mislead by the numbers presented--they have little relevance to how CD-Rs are typically stored.
Standards (Score:5, Insightful)
I have some Kodak Gold CD-Rs stashed away for archival masters. I have no idea how long the DVD+Rs and DVD+RWs will last.
Re:Standards (Score:5, Interesting)
DVD media should do better than CD, if only because the data layer is completely encapsulated, as opposed to covered in thin lacquer like CDRs. This assumes, of course, that the edges are similarly well sealed. Looking at my (DataWrite 8x plain white printable) DVD+Rs, that seems to be the case - the data layer stops about 1mm short of the edge of the disc.
Only one solution for long term data storage... (Score:3, Funny)
...papyrus. That, or clay tablets. Nothing else comes close. And I'm not joking.
Re:Only one solution for long term data storage... (Score:2)
Well, my data only has to last another 50 years or so. After that I'll certainly not care.
Clay tablets bring new meaning to the term data density with their low bytes per pound.
Re:Only one solution for long term data storage... (Score:2)
Damn... (Score:3, Funny)
As Usual... (Score:5, Insightful)
I've yet to lose data to media degradation, however I once lost some important accounting data to a hard drive crash, followed by two ZIP disk backups that were killed by "click-death". One in a billion shot, I guess. Well, I didn't exactly lose the data, I had hard copies on paper, apparently the only semi-permanent storage media that's trustworthy.
Re:As Usual... (Score:5, Interesting)
I worked for a museum that preserved such materials, and always wanted to establish a program not just to copy older videotape to newer analog formats (which already existed) but to copy and RE-copy those digital tapes on a two-year cyclical program; the digital data wouldn't degrade during the transfer, and by essentially replacing the media containing the data on a regular basis, we'd have a good chance of saving the material long-term.
I never got approval for a simple reason: tape stock is expensive, staff is expensive, and coordination of such an effort requires diligence. Similarly, you could use CD-R/DVD-R to back up your material and re-burn the discs on an ongoing rotation, but most people don't have that kind of discipline even if they have the money.
For me personally, I've found the best approach is to maintain the data on a redundant RAID array, with occasional backup to DVD-R. This way, the data itself will outlive the death of individual local drives, while the DVD-R only needs to serve as a short-term disaster-recovery solution.
Of course, once my critical dataset gets large enough to require more than a few DVD-Rs, I'll probably get lazy...aren't we about due for a new format by now?
Re:As Usual... (Score:3, Interesting)
Re:As Usual... (Score:3, Interesting)
CD-RW uses a phase change crystaline latice to store data, not a volatile organic dye. This means that the chemical breakdown seen in CD-R's is not going to be present in a CD-RW. For this reason I think that CD-RW is a vastly superior archival solution, of course it doesn't work in areas where WORM is mandated (such as securities firms) but for something like home backups it should seriously be considered. Unfortunatly even with the recent flurry of attention to CD-R archival qua
Comment removed (Score:5, Interesting)
Re:black cd's (Score:3, Funny)
Useless (Score:5, Informative)
As others have noted, the technologies used in the media are never printed on the packaging. Furthe, like many commodity items, the wrapper has nothing to do with who actually made the media. One spindle of Brand Y disks can be made by Manufacturer A, and the spindle twice its size, with the same labelling, also from Brand Y- will be made by Manufacturer Z. It is extremely difficult to be an educated consumer under these conditions.
It happens in lots of other places- gasolene is not "made" by Mobil; Mobil, Hess, Shell, Sunoco etc contract to area distributors. The distributors buy from whoever is the cheapest or distributes to their area; they slosh-mix any company-specific additives, if any, on the way to the station. Milk? Guess what- federal law requires that the bottling plant's registration number be printed on every bottle of milk. Next time you're in the store, notice how the brand name and generic store brand milk have the same prefix on that stamped number? Notice the brand name milk is pretty expensive compared to the store brand stuff? Dirty little secret of the milk industry, in plain view.
When I need CD-R/DVD-R media, I don't want to have to spend an hour sitting on some webforum reading posts to find out what the most reliable media looks like this week and where to buy it. I want to walk into a store, see "gold type cyno-whatever", see it's $2 more for a spindle of 20 than the other stuff, and walk out.
Though I'm sure there is collusion among manufacturers at the moment, it's only a matter of time before one manufacturer realizes they can market their product based on media type/chemistry thanks to this report educating buyers (the major PC mags will probably pick this up in an issue or two).
What bugs me is how bad my DVD-R disks SMELL. I have to hold the spindle at arm's length when I open the cakebox, and leave the room until the disk is done, because it reeks. I want to know what the hell makes it smell so bad...or, then again, maybe I don't...
Re:Useless (Score:5, Informative)
Re:Useless (Score:3, Informative)
www.american-digtal.com -> Mitsui 80 M gold $82.36/100
Conway Yee
Re:Useless (Score:3, Insightful)
followup (Score:2)
DVD-R media is probably the hottest market right now (even NIST/LoC admit CD media is nearly useless in terms of storage capacity), and note that NIST used the least number of samples, couldn't get any information on composition other than "it's Cyanine based" (gee, thanks), and DID NOT name this mysterious "D2" sample that was so much better than the others?
Sounds like NIST doesn't want to burn an
Re:followup (Score:3, Interesting)
While it was not named, I think I can guess. Mitsui/MAM-A. They are stating now that their DVD-Rs are silver/phenothiazine based, which is the same chmistry that kicks serious butt with CD-Rs.
What will be interesting is to see if this chemistry holds up with Blu-Ray. The shorter wavelength may or may not be compatable with the dye.
Re:Useless (Score:2)
Now not only can you get high off the markers to label the discs, but you can get high off the discs themselves.
Re:Useless (Score:5, Informative)
I'm a duplication specialist in Redmond, WA. I handle and analyze nearly all existing products in the world.
Why DVD's smell so freakin' bad, is beacause they are two half-discs 'glued' together. I dupe these by the thousands; some brands, like Taiyo Yuden, will smell better than Mitsui Maotsu(Mam-A).
For the best products on the planet:
www.dsgi.com
Get educated about it, and you will appreciate your results.
later
Taiyo Yuden (Score:5, Informative)
afterdawn had a discussion on CD-R brands [afterdawn.com] a while back. In short, go with Taiyo Yuden. And to identify Taiyo Yuden [cdfreaks.com]?
Readers (Score:4, Insightful)
I still have tons of 5" floppy disks around, and I'm sure the data on them is usable, but getting it off is another story.
Re:Readers (Score:5, Funny)
That could be a problem, since the only drives around are for 5.25" disks.
-Anonymous Phil
Forget it! (Score:3, Insightful)
In fact, if I had enough space, I would back up my commerically manufactured CDs and DVDs, given the horror stories I've heard about their crappy longevity. The MP/RIAA wants you to re-purchase all the content they've sold you every 5-6 years. Screw 'em.
Re:Forget it! (Score:2)
Re:Forget it! (Score:2)
Re: (Score:2, Interesting)
Flashlight Test, The (Score:3, Insightful)
Is it true with many things that reflect light, that the less light it throws back, the more it ABSORBS?
--meaning here probably, that absorbation is what degrades the medium.
I mean, I've had both "dull" and "blinding" discs, (some light-green one's that basically didn't shine at all once "shone on",) and the EXTREMELY reflective one's, that would practically blind you, to some extent.. --I mean, when angled towards a tungsten bulb, or flashlight, whatever..
-Get the drift? --Maybe this is of some importance, don't ask me.. I always go for 'the shiny' one's; as I've suspected them to be "better"..
Re:Flashlight Test, The (Score:3, Interesting)
I *presume* that as the media ages, the margin of error slowly shrinks to the point where your media is now unreadable. As all you're reading is either
- the reflected light from the reflective layer
or
- the absence of reflected light due to the dye
Discs with lower reflectivity will end up useless f
Re:Flashlight Test, The (Score:3, Informative)
While using a flashlight on a disk may be worth doing, the results may not mean what you think they will. First, light from the flashlight is either reflected, absorbed, or transmitted. If you shine light through the disk, you can see pinholes that could be a sign of poor manufacturing or subsequent damage. It is not the absolute reflectivity of the disk that matters it is the contrast.
Imagine disk A reflects 90% of light for a one and 80% of the light for a zero. Disk B reflects 70% of the li
Look at it like this (Score:2)
the study is not really useful without brand names (Score:3, Funny)
the only one I can find right now in three websites (verbatim, imation, tdk) is that tdk uses metal-stabilized cyanine dye in their CD-Rs. that would make them a "c5" sample, which is fairly resistant to stray UV, but temperature/humidity sensitive. to me, TDKs sound just a little bright, but it's not bright enough to be a car-only disk.
verbatim used to boast of using blue azochrome dye, which In The Beginning was prized by burners who wanted accurate audio. verbatim blue is still out there in the "digital vinyl" series at least. that would be an "S1" or "S3", who knows which, which has some issues with both temp/humidity as well as strong UV. Sounded good and neutral.
what I haven't seen is the richer, "tube" toned deep green of Sony and 3M 2x/4x disks of the late 90s. never knew what it was chemically, either. I'd order a case of them if I could find 'em. no "scatter-shatter" sound on those disks.
the only thing I've had issues with are budget CD-Rs with a barely-visible green coating to this point. they go away in a dark, double-shielded player in a console in the car, and have shelf life issues in the house as well. After two years, they wouldn't even pass the pre-record test of the burner. Never again.
but I can't buy for known permanance, despite NIST, because they don't call out whose disks they tested. Hope somebody consumer-oriented gets an idea from this, and beats 'em up with brand names attached. there's going to be somebody out there who has used junk disks forever and never lost a one sitting open under the cat hair on the window ledge, so anecdotal evidence is, uhhh, not reliable. even mine.
Re:the study is not really useful without brand na (Score:3, Informative)
The terms you use correlate to accuracy of reproduction of various frequency of audio. Audio stored on a CD (I"m not talking about CD with mp3 files on it) is stored as a sequence of samples... that is to say strictly as a time-domain function.
for backups (Score:3, Insightful)
I change hard drives every few years, since there's a constant attrition rate, anyhow. Plus they just keep getting BIGER and CHEAPER every year.
to me, optical media are for sending data to others, not for gathering dust.
Isn't it in part a question of the CD readers? (Score:3, Insightful)
Really, the big advantage stone tablets have is huge amounts of redundancy, but a very small amount of actual data. DVDs could have multiple repetitions of the data on different parts of the disc for fault tolerance.
What about CDRW? (Score:3, Insightful)
I recently starting going through some of my old CDR's and I noticed that 3 of my 4 CDROM drives had trouble reading a certain disc. I try a 4th drive (DVD+RW), and it reads it just fine. My guess is this means that the disc is starting to die, and now would be a good time to back it up again.
Media is fallible... (Score:3, Interesting)
One small thing, which I've yet to see but maybe some slashdotter can point me to - is there any way, under windows, to automagically mirror a folder on one drive, to another folder (on another drive). I don't mean a full RAID1 of the entire disk, but the few 100mbs that are crucial. Sacrificing 160GB HDD space just for that seems like overkill.
Kjella
Re:So when will my cheap CDRs from the late 90's d (Score:4, Informative)
Re:pffft (Score:3, Insightful)
Re:pffft (Score:2)
Re:HTML Link (Score:2, Insightful)
I know I shouldn't feed the trolls, but...Wow, that's mature. It is an open standard, with free (both open and closed source) readers for virtually every platform in existence. The paper contains images, charts, and so on. PDF is a perfectly acceptable choice, particularly if it was a report which was not originally designed for the web.
Unfortunately, seems they slightly missed the point- the charts and other line art...well...aren't. They're screen-resol
Re:HTML Link (Score:3, Informative)
Re:government? (Score:5, Funny)
Re:government? (Score:2, Funny)
Re:government? (Score:5, Funny)
Re:The reverse of light and heat (Score:3, Insightful)
Several people have suggested the idea of storing media in the fridge or freezer. This is not something to be done lightly. Yes, the colder temperatures would, all other things being equal, reduce the rate of chemical reactions. But in the real world, the fridge or freezer is a magnet for condensation and frost. If you put the disks in a freezer with auto defrost, then they can also be subjected to thermal cycling which is very bad. I am also dubious about a fridge/freezers suggested ability to sur