Say Goodbye To Your CD-Rs In Two Years? 707
Little Hamster writes "According to an article on cdfreaks.com, a test done by the Dutch PC-Active magazine showed that among 30 different CD-R brands tested, a lot of them were already unreadable after twenty months. This is shocking, and makes me wonder how should I backup my data, photo and music collection."
but something is missing... (Score:5, Interesting)
Re:but something is missing... (Score:5, Insightful)
It doesn't really matter how fast the reading laser moves along the media, so why would it matter how fast the recording laser moves?
Re:but something is missing... (Score:5, Informative)
Re:but something is missing... (Score:3, Informative)
The machine is usually a Sony CD-RW CRX145E, recording at 10X and re-writing at 4X. I have faster burners on other machines, but those are newer, so I can't yet vouch for their quality.
Re:but something is missing... (Score:3)
Re:but something is missing... (Score:5, Insightful)
Re:but something is missing... (Score:5, Insightful)
Re:Mistake? (Score:3, Insightful)
Re:but something is missing... (Score:5, Interesting)
I still have a SONY CDR burned at 1x in 1997 ! and still works just fine. (but useless old software anyway)
Re:but something is missing... (Score:5, Insightful)
Every CD burner (like every real-world device) has a certain amount of error. The device decides to turn the laser on or off, and there is a delay before the laser turns on or off. This small delay varies with heat and other factors within the device and varies with the component tolerances from device to device.
This error rate is over time, not distance. So, if the CD is rotating slower, it doesn't move as far during the error period. This results in a burn which is closer to perfect, that is it has less error distance than a higher speed burn.
Then there is the completeness of the burn; with a brand new good quality drive it shouldn't matter, but how many of you have a brand new plextor?
And of course there's also the CD media. If you bought the 10 cent bulk discs and expected them to last, shame on you. I record at slow speed to the old dark-blue verbatims whenever I can, and after 7 years I havn't lost data yet.
Re:Which CD-R(W) brands are worth getting? (Score:5, Interesting)
Also, keep your burned discs out of direct sunlight and excessive heat, both which will cause the top foil layer to come off. Even quality media will give out on you after exposure to the elements.
Re:Which CD-R(W) brands are worth getting? (Score:5, Informative)
Re:but something is missing... (Score:5, Informative)
I've always wondered if this [burning at 1x speed results in better CD's] is actually true or not.. I have yet to see any actual evidence to back up this claim...
Well, head on over to cdfreaks.com [cdfreaks.com] website and take a look at the results of some tests. For the lazy among us, burning at 4x resulted in more C1 errors in every test posted (on page 1, page 2 timed out) than burning at a higher speed (usually 40x, but one test was at 52x). A comment on page 2 indicated on person did 4 tests, and half said burn at high speeds and half said burn at lower speeds. Overall, the small sample of results indicated that burning at low speed usually makes things worse, not better. Surprising huh?
Re:but something is missing... (Score:3, Insightful)
BTW, I had some audio cds stored in my car that lasted over 5 years. I finally threw 'em out because they started skipping on some tracks.
Re:but something is missing... (Score:5, Interesting)
I agree.. Slower recording speeds will usually improve the contrast ratio of the resulting recording.
One can confirm this by making several cd-r's writing at different speeds using the same type of media, and then visually comparing the cd-r's data surfaces, (For recorded areas, Darker is better).
A fair number of CD recording programs DO NOT have a VERIFY cd-r contents option after a burning, and is a major pain in the ass. This problem got me good when I used some 12x Office Depot media for saving some TV show mpegs. Bad move, :-(
I found out months later, that 50% of initial recordings had one or more non recoverable bad spots.
Nero is the only mastering program I know of, which will verify cd-r contents after burning :-),
:-( .
But it doesn't do it for all recording formats
Slower recording speeds not always better (Score:5, Informative)
Does it matter? Yes. Is slower always better? No.
Rather than re-hash this, please see:
In the CD-Recordable FAQ [cdrfaq.org].Quick summary: higher speeds require a different "write strategy" than slower speeds. Different media formulations are optimized for a particular write strategy, so writing slower than the optimal speed can actually produce inferior results.
The choice of media and recording hardware has to be taken into consideration. In any event, this has relatively little to do with disc deterioration. A disc that's better to begin with won't show the effects of physical deterioration as soon, but if the top lacquer coat isn't as close to air-tight as materials allow, it doesn't matter how you write the disc.
Re:Actually 2x (Score:3, Funny)
Oh no! (Score:3, Funny)
Re:Oh no! (Score:3, Funny)
Does DVD-R last longer? Let's see, I'll need about 200 blank DVDs...
Re:Oh no! (Score:3, Funny)
Re:Oh no! (Score:4, Funny)
Re:Oh no! (Score:5, Insightful)
Re:Oh no! (Score:3, Funny)
Priorities, my man, priorities!
Re:Oh no! (Score:5, Funny)
I'd explain, but it takes too long given that I'm typing one-handed.
Re:Oh no! (Score:5, Insightful)
-Barry
Re:Oh no! (Score:3, Insightful)
What a silly thing to say. Taking it seriously for a moment - There are lots of people who disapprove of pornography, for one reason or another. The political left (feminism) considers it exploitative, the political right (conservative religious) consider it amoral, and women (even geek women) don't tend to be consumers of pornography. Since Slashdot certainly has its share of political left, right, and women, it's easy to see that no one t
Re:Oh no! (Score:3, Insightful)
Sure there is. Our love of bandwidth.
set your prefs to mod "Funny" down (Score:4, Informative)
The biggest benefit is that it cuts WAY down on the number of +5 posts, so you can get straight to the key comments if that's all you want. It's cool when the home page says "24 of 215 comments" but when you click in the Funny modifier filters half of them out and you end up only having to plow through 12 :)
Re:set your prefs to mod "Funny" down (Score:3, Funny)
What's really strange is that ever since I excluded all of the articles from the front page, slashdot doesn't seem to ever update anymore.
Needless to say, my productivity has gone through the roof.
simple (Score:3, Informative)
Keep upgrading your Harddisk from time to time and backup data from old HD to new one.
Re:simple (Score:5, Interesting)
Re:simple (Score:4, Informative)
All archival quality CD-R's use phthalocyanine, it is the only stabilized dye known to last more than 100 years. Gold is the absolute best reflective layer available because it is almost completely non-reactive.
The combination of those two is the only way to get a true 200 year archival life CD-R. They aren't "cheap", usually less than a dollar each but 85 cents in a 100 pack isn't unusual. Try this google search [google.com]. The second link is a place selling 100 packs for $82. That's 82 cents a piece for a CD-R that should last until the year 2200.
If you're willing to live with slightly less... I managed to pick up a pack of Fuji CD-Rs with a phthalocyanine dye layer and aluminum reflective layer. Fuji seems to think they will last 100 years, but I have my doubts. Still the #1 reason CD-Rs fail is the dye layer, not the reflective layer.
Re:simple (Score:3, Informative)
Both Fuji and Memorex have TY and non-TY discs. But you can, as you say, check the packaging for the country of origin. As far as 50- and 100-spindles go, every "Made in Japan" I've bought from these two brands has been TY, as reported by CDR Identifier [google.com].
--
Dum de dum.
Mitsubishi and TY (Score:5, Informative)
From a little googling, I now see that they signed a Memorandum of Understanding with the Rainforest Action Network promising to change their ecologically unfriendly corporate practices. Here is the link:
http://www.ranamuck.org/news7.01mitsi.htm [ranamuck.org]
Provided the humungous Mitsubishi zaibatsu is living up to their promises, I have no problems now recommending Mitsubishi Chemical CD-Rs. Everything I said about TY goes double for their disks.
The reasons why TY and Mitsubishi CD-R blanks are so good and so compatible are the fact they use a much darker dye than the Taiwanese manufacturers do. Yamaha suggested the use of Mitsubishi Chemical CD-Rs with their "Disc T@2"-equipped burners because the graphics would show up better. They are a better choice for maximum compatibility for the same reason they are a better choice for "Disc T@2". The more visible the dye layer is to the naked eye, the more visible the dye layer is to a CD-ROM or CD player's laser.
I wish I could back my assertions up with a whole list of studies, but I am basically speaking from several years of my own experience with CD-R blanks. I don't see as many CD-Rs made by TY going bad as no-name Taiwanese crap does.
Re:that's not good enough. (Score:5, Informative)
MAM-E Gold Ultra CD-Rs are guaranteed by the manufacturer to last for at least 200 years. [mam-e.com]
Happened to me (Score:2, Informative)
To make them last longer... (Score:2, Informative)
treat them like a mushroom and keep them in the dark.
I have many CD-R discs that are still quite readable despite being 4-5 years old. On the other hand, I've seen a disk erase itself in less than a day when left in direct sunlight, and many disks will slowly degrade at light levels found in most human-occupied spaces.
Re:To make them last longer... (Score:5, Informative)
RTFA. That's what they did; they kept them in a closed cabinet for two years in their original packaging. Some brands were toast after two years.
The fact that your CD-R discs appear to be readable after 4-5 years isn't a useful data point. These guys used CD analyzer hardware (CDA-3000) to check the quality of the discs. CD's have error checking and the damage may not yet be noticeable to the end user until later.
error stats (Score:3, Interesting)
I suspect that CD drives also have this capability, just that software doesn't bother to use that info. Actually, most software doesn't even appear to check for non-recoverable errors so I
floppy disks (Score:3, Funny)
Re:floppy disks (Score:5, Funny)
Cuneiform Tablets (Score:5, Funny)
Re:Cuneiform Tablets (Score:3, Funny)
Re:floppy disks (Score:5, Insightful)
Ahhh, any veteran of the Commodore 1541 floppy drive can tell you what this is: alignment errors. You see, the head is moved using these little step-motors. With use, the motors drift out of alignment, meaning the head moves somewhat less (or more) per "kick" than it's supposed to. As long as it's the same motor, that error occurs on every operation, so there's no net effect. (That is, sure, the data's in the wrong place. But during read-out, the head will seek to the (same) wrong place. So no error.) But move that disk to another machine, whose step-motor has a different alignment, and BAM! read errors.
Fans of the C1541 will remember what happens when that drive found an alignment error: CLACKETY-CLACKETY-CLACKETY-CLACKETY-CLACKETY-CLAC
C= 1541 (Score:4, Funny)
I had a 1541 that wouldn't stay aligned for more than a couple of hours. One day, I smacked the drive in pure frustration while it was gronking away - and the sonofabitch loaded.
From that time forward, SOP for loading any C=64 program was:
1) load *,8,1 [enter]
2) watch drive light come on
3) swat drive
4) PROFIT!!!!
DG
Re:floppy disks (Score:3, Insightful)
Re:floppy disks (Score:4, Funny)
Xerox has gone to all the trouble. (Score:3, Informative)
According to this ancient Seybold report [seyboldreports.com], Dataglyphs can achieve densities of a kilobyte per square inch.
DataGlyphs were featured in this /. article about chess playing scanners [slashdot.org].
Blah, physical backups (Score:3, Funny)
Re:Blah, physical backups (Score:5, Funny)
Re:Blah, physical backups (Score:3, Interesting)
Scramdisk was an open source program to create encrypted containers (mount as driveletter in windows) in
Be the first to post a FLAC (lossles audio compressor) of the next hot EMINE
Use floppies! (Score:2)
Tape Drives (Score:5, Insightful)
Re:Tape Drives (Score:5, Informative)
Tape isn't slow. (Score:3, Informative)
harddisk rack back-up (Score:4, Interesting)
Re:harddisk rack back-up (Score:5, Funny)
With respect Sir, most people you know don't download nearly enough pr0n.
CD = Inferior Storage Technology (Score:5, Interesting)
1. For the average person, a file is in some way less real if it is on a hard drive, and more real if it is on a CD, where it is a physical object they can touch.
2. Familiarity with CD's due to long term use on music CDs.
3. Vastly superior marketing to hard drives.
Removable hard drive bays should be standard on all PC's. Once you are used to these, the Hard Drive is just a Cartidge to plug into the PC. Data is easily backed up, and a Hard Drive in closet is safe.
Hard drives are faster, take up less space, and are very cost competative with CD's. I am unclear why CD's are popular with the tech savvy crowd. It's an inferior storage technology.
Re:CD = Inferior Storage Technology (Score:5, Interesting)
I can put a CD in its jewel case, then drop it off a desk and on to a concrete floor--and I can expect the data to still be intact.
Hard drives are impact sensitive, and still prone to failure after a year or two.
Also, if I need to move a file from point A to point B CDs are convenient and lightweight--everybody has a CD-ROM drove. Subsequent to that, many people prefer to make backups to CDs because they are a technology that they already have installed for other reasons. Rhetorical question by hypothetical individual: Why would I go to the trouble and expense of another backup method when I already have a CD burner?
Bad CDs also make excellent coasters.
Re:CD = Inferior Storage Technology (Score:5, Insightful)
So please, don't call an HD that is in the same computer, or even the same server rack, your backup. However, a network connected machine on the other side of your building will do just fine.
Re:CD = Inferior Storage Technology (Score:5, Funny)
That's what I tried telling those RIAA bastards but they won't believe me. Putting my CD backups on Kazaa was simply the safest backup investment I could've ever made. Then they came along and labelled me a pirate! A pirate!? I'm just trying to backup my valuable data! Where better than in a distributed format strewn all across the Internet? Even if the entire United States were to blow up I could still retrieve my data from China! Please RIAA, think of the backups.
Re:CD = Inferior Storage Technology (Score:3, Insightful)
It's no longer a hard problem, but everyone seems to have decided that they already know the correct solution
OTOH, just imagine what a huge surge of bytes that would put on
Easy backups (Score:5, Interesting)
Storage conditions? (Score:5, Interesting)
I've got a whole load of burned CD's that I created up to about 5 years ago.. and on varying quality of media, and a lot of them aren't any problem.
I suppose storage is the key thing, keep them in a dark cool place will help them last just that bit longer (unless you have a case of those little bugs that like eating the data layer).
Although they are of a similar tech, what about DVD recordable disks? I've got plenty of those now... but if I keep doing what i've been doing over the years and backup my backups onto newer media then I'm not too worried.
Just my $0.02
Break out the Brillo (Score:5, Informative)
This would be as good a place as any to mention TDK's Armor Plated DVD Media [tdk.com], which are supposed to keep on working even after having been scoured with steel wool pads. Also, Verbatim makes a line of scratch-resistant [verbatim-europe.com] CD-R media.
Obligatory "Good Omens" reference (Score:3, Funny)
More of the article should be translated. (Score:5, Insightful)
Re:More of the article should be translated. (Score:3, Informative)
The part they translated from the online article is pretty much all the substance there is in it. The actual results and further information aren't there.
The last paragraph of that:
In the September issue of PC Active, that will be in stores on 22 August, the shocking results are described in detail. Besides the possible causes of losing data over time we also a give a number of valuable tips to preserve the data on a writeable CD for the future. On the free cd-rom there is also a program to discover the
Save it to Film (Score:3, Interesting)
Don't take it too seriously (Score:5, Interesting)
Or, rather literally translated into English: "Our sample shows that there is a lot of junk on the market. We have found cd-rs that should never have been for sale. Possibly it concerns rejected batches." Which suggests to me that the correct heading of this article should be: CD-Rs are like everything else: you get what you pay for.
Re:Don't take it too seriously (Score:5, Informative)
Long story short the rule of thumb was like this: Green CDs have a life of ~5 hours. Yellow CDs ~20 hours. The DARK DARK Blue cd's (not light blue, the only brand I know of like this is Verbatim) *600* hours.
The price increases correspondingly as well. I found the best solution was to use blue's for backups and critical things, and regular commodity cd-r's stuff for day to day things.
No consistency :P (Score:3, Insightful)
I used to buy only TDK. Then I had to switch to Verbatim when TDK started getting cheap on me. Now I'm using Mits
Unanswered Questions (Score:5, Insightful)
Were they all stored in the same place?
Were they all burned by the same CD burner?
Were they all burned from the same source (a single CD, hard drive, network, etc.)?
30 CDs sounds like an epidemic, but since they were all burned at the same time twenty months ago, there could be a lot of other reasons why all of these discs would go bad. If they were all burned at the same time, then they're effectively talking about one batch, regardless of how many different CD-R brands were used in that single batch.
Does the Dutch article cover this or is this just a scare story?
Re:Unanswered Questions (Score:3, Informative)
Re:Unanswered Questions (Score:3, Informative)
And here is the key.
I've seen other tests where CD-Rs can't be written reliably after sitting around blank for a few years or artifically "flash aged" using elevated heat &c.
That matters to me a bit, but what's much more important is how reliable the data can be read after *being written*, then stored for years.
I use Kodak pseudo-golds (they don't make the real gold on gold ultima anymore) for anything I care about. The discs should be good, but they are also actuall
This is not surprising. (Score:5, Funny)
Take now into account earth's rotation and its magnetic field. It induces an albeit very slow movement of the molecules - the data layer degradation. The same effect causes btw certain currents in the Pacific oceans. While the movement is very slow and in the case of the ocean not very important, it does cause damage after a certain amount of time in the case of a CD-R. You should remember that the scale of the information storage units on a CD-R is in the nanometer range. The information is just "washed away" in an entropy-like effect.
However, you can slow this movement down. The molecular movement in the data layer is directed. So it can be reversed to a certain degree just be placing the CD-R the other way around. So, all you have to do is to mark the position of the CD-R in your rack exactly. And reverse it's position every month or so. This can increase to the lifetime of a CD-R about 150 percent. More can't achieved (in normal environment) because electric machines like your computer etc. create their own electro-magnetic fields. And the effects of these varing fields are much more difficult to negate.
BTW: the 100 percent wrong place to store your CD-Rs is on the top of your CRT.
Offsites (Score:4, Insightful)
It's peace of mind knowing that if, heavens forbid, anything catastrophic were to happen to your place of residence, or if burglars were to take your computers and disks/tapes, then you would at least not have completely lost all of your critical data.
You get what you pay for. (Score:5, Informative)
FWIW, I can't remember having a single CD-R go bad. I've had some scrathed ones which took a while to read because the reading drive slowed to a crawl, but I got the data nonetheless. I even recently found what must have been one of the first CD-Rs I've ever burned. Must have been from around '96 or '97, it had my backup copy of Duke Nukem 3D on it, among other stuff, and everything read fine (the disc was a Sony CDQ-74CN).
Re:You get what you pay for. (Score:3, Interesting)
To be extra safe, I run two CD-R drives to write two copies of the data to two different brands of CDR medias at the same time. Then I also overlap the data for the next batch -- taking half the data from the previous CD, and adding new data to fill the new one. So that any given
Not surprising, and not new (Score:5, Informative)
The first thing to understand is that WORM systems, true WORM systems, not the Magnetic-Optical pseudo-WORM systems, are built on ablation of material in the disc itself. In other words, you burn holes in the disc revealing a lower layer that is reflective. In the case of most discs, and Kodak especially, they were gold on the reflective layer for long-term stability. Various tests of accelerated degradation were performed in both climate stabilized and non-stabilized situations, and at worst, the discs were stable for 100 years before any error correction was necessary.
We decided to perform the same kind of evaluation of CD-Rs, and found that brand varied greatly. The best were stable for 3-4 years, the worst only 6-8 months if the climate changed dramatically. In addition, UV exposure had a radical impact on the life-span of the disc. Further research found out that the problem was the natural instability of the organic dyes that were used in the disc layers.
Basically, if the disc wasn't perfectly sealed (look at the work done in the referenced article, and how it starts at the edges), oxygen would get in and react with the dye, which would change it's characteristics relatively quickly. It doesn't take much before the dye structure collapses, and data becomes unreadable after a short period. While I suspect the dyes have gotten better over time, they're still organic last I knew, and still subject to degradation by contact with air. Quality control is the only thing that will get you anything here, and I suspect even the best dye-based discs can't make it past 20 years unless exposure to UV is totally eliminated.
What Kodak had developed was what they called "Century Discs", which were basically scaled down WORM discs, but in CD-ROM format. They were gold inside, non-reactive, and well made. They did, however, require a very expensive writer because they needed more power than a CD-R drive could ever hope to provide to force the burn away the spots. They were, however, readable in a normal drive.
That's just my experience, but everytime I've seen an organization talking about "archiving" on CD-R, I have issues with it. It's fine for "backup," where the data cycle is shorter, but true archival purposes (for example, financial data), it won't cut it. You either need to use WORM, or tape. Tape is, however, subject to problems over the cycles as well, witness the failing properties of 9-track tapes written by NASA in the 1970s (heard first hand, not sure where to find it written up). Linear-write systems are better than helical.
Just a few thoughts, but this is not an easy issue. You have to understand what you're storing, and how long it has to be readable before you consider an actual medium for storage.
Re:Not surprising, and not new (Score:3, Insightful)
They are a phase-change medium, either the substrate is crystalline or it is amorphous. Thats not something that's likely to change with time or degrade like an organic dye.
Re:Not surprising, and not new (Score:3, Interesting)
panasonic phase change is crap... (Score:3, Interesting)
the media and technology is shit. period. it died off for good reason.
every single one of the discs died within a year with unrecoverable errors under even light occasional use.
even the crappiest CDR/RW technology I have seen is light years beyond that panasonic phase change crap.
ps i still have the drive and dead media sitting around, if anyone wants to buy it cheap...
Re:Not surprising, and not new (Score:3, Funny)
You mean encoding selections from the 1978 John Travolta and Olivia Newton John movie on the outter tracks of the disc? Brilliant! Even O2 won't react with John Travolta.
As far as removing Grease, the Church of Scientology can remove anything it wants. Its the perfec solution!
Brand and manufacturer? (Score:4, Informative)
Back when you could still get them, I burned all my important data onto Mitsui golds. They seem to be working still, after sitting around for 5-6 years. Similarly with the Mitsui silvers and Kodak silvers. All these used a pthalocyanine dye, which is supposed to be more stable than the cyanine (and cost more
Which brands are good today? That's rather hard to tell, since even within a single brand you're probably going to find a bunch of different manufacturers, unless you're buying one where the brand is the same as the manufacturer. I've seen tons of different manufactured Sonys; Taiyo Yuden's and Mitsui's showing up as Memorex's (very rare, most of the current ones are Prodisc I think and I've seen a lot of Riteks in the past). 'Made in Japan' seems to be a good sign though, instead of 'Made in Taiwan'.
Personally, I save the cheapo ones for throw-aways. Burn to listen in my car for a while, to mix and match and avoid wear and tear on originals. Scratching them up really doesn't matter, they're not that critical. Anything important I try to keep on (supposedly) more long-lasting media, and that gets handled with care. So far, 5+ year backups have been brought back up and data read without any problems. Whether that'll be true of the more current disks in another 5 years I really can't say.
Brands? (Score:3, Insightful)
Lesson 1: Never get a CD-R w/o any printing on it. I got some (TDK, I think) that were just silver on the top, no branding or anything, and they burned just fine, but I found out later they could be scratched VERY easily. Scratched on the top, mind you. Apparently there was no protective layer over the foil, and you could just scratch it right off. I think they were meant to be printed on by some kind of CD printer.
My TDK's that I burned 2 years ago with the white surface (w/ branding) seem to be perfectly fine though. I also don't seem to have any problem with any imations that are as old.
I have one 2-year-old CD in which the foil appears to be harboring some kind of fungus. The brand is "K Hypermedia," I think I got it for free or really cheap. You probably get what you pay for. But the "fungus" is only on part of the edge, so it still plays fine. I have a handful of others of the same brand, which look okay.
disclaimer: I take semi-good to pretty-bad care of my CDs. They are routinely left out on the counter, desk, or wherever, and sometimes stacked in tall piles, when I don't feel like looking for the matching packaging.
Magneto Optical Is The Way To Go (Score:3, Informative)
The drives can be had for roughly $257 for internal IDE [zones.com]. I didn't shop around hard, but you can get a 5pack of 1.3GB disks for $95 [zones.com] that's about $0.014/MB, not too shabby. They also make high end solutions with 9.1GB disks but the drives are remarkably expensive. If I were more serious about doing backups, magneto optical would be the way to go.
Paper (Score:3, Insightful)
I doubt it... (Score:5, Informative)
The other thing to consider is that DVD-R/+R technology is dropping though the floor. I bought a Pioneer A05 for $320 in January and today the A06 is going for $229. [newegg.com], and remember I bought this thing from the same place I linked to. I don't know how DVD-R is for archival, but my point is that at the rate the technology is falling in price, CD-R may not be around much longer anyway.
In any case, I found a rather excellent guide on the different tyes of CD-R media. It goes over all the dyes, their manufacturers, theoretical lifespans of the dyes, etc. I recommend a visit...
http://www.cdmediaworld.com/hardware/cdrom/cd_dye
100-200 year CD-R blanks are available (Score:5, Informative)
-
MAM-E Gold Ultra [brennershop.de], about Eur. 1.15 each.
-
Mitsui Gold Ultra [mitsuicdr-store.com], about $1.60 each.
Kodak used to be in this market, but seems to have exited it.The key here seems to be dye type. Phthalocyanine has slower writing speeds but longer storage life; Cyanine has higher writing speeds but much shorter storage life. The "archival grade" CDs also have gold reflecting layers and a tougher substrate.
There are also "Medical grade" CD-R blanks, but they're essentially the same as the archival ones.
There are programs which will read the ATIP information from a blank, telling you what the manufacturer, max writing speed, and dye type is.
Taiyo Yuden (Score:4, Informative)
Taiyo Yuden were reckoned to be the best manufacturer. they make discs for lots of different manufacturers, but you don't know 'til you get home and get yr CD writing software to read the code off the disc and tell you who the manufacturer is, bcos it aint gonna tell you on the packet. and different sub models of disc can be made by different manufacturers.
I think TDK even had the same models, with some made by Ritek (the worst quality) and some made by Taiyo Yuden. there was a court case against them for this.
I buy a single TDK disc, take it home and check it, and if its made by Taiyo Yuden I go back and buy loads of that same model disc, and have been able to get the people in the shop to say they'd take the discs back if they weren't Taiyo Yuden (a large consumer-space chain in the UK, I shan't name them incase they read this and stop being so remarkeably fair)
Re:Taiyo Yuden (Score:3, Informative)
In reality, 50% of the TDK discs I buy (model: CD-R80, currently with an item code of CD-R80CMEB but many other items codes too) are manufactured by Taiyo Yuden and 50% claim to be manufactured by TDK
These articles should be useful...
'CD Factories':
http://www.cdmediaworld.com/hardware/cdrom/cd_fac t ories.shtml [cdmediaworld.com]
'CD-R Quality':
http://www.cdmediaworld.com/har [cdmediaworld.com]
A little history... (Score:3, Interesting)
disc label
protective coating
data layer (usually pressed)
protective coating
Then at the end of the eighties, I don't recall exactly what year, but it was adopted by various cd makers till eventually all, the price of CD's dropped dramatically, almost in half.
The reason for this was the fact that the top protective layer wa
Re:A little history... (Score:5, Informative)
disc label
protective coating (laquer)
Aluminum layer (sputtered on)
data layer (pressed into the next layer when injection molded)
polycarbonate injection molded disc
To vary from this is a violation of the Phillips spec, and you are not allowed to put the Compact Disc logo on the resulting product.
What you probably noticed was the laquer layer was thick when we started making discs, but over the years laquer has improved to the point that only a very thin layer is needed.
If you leave out the laquer entirely, the aluminum oxidates rapidly, rendering the disc useless.
Re:A little history... (Score:3, Insightful)
Re:That makes me wonder (Score:5, Informative)
Laquer = Bad Idea (Score:5, Informative)
This Site [svbxlabs.com] has been kicked around slashdot lots of times and depicts a man, a dremel, a CD and 30,000 RPM's of angular velocity.
Re:Crap CD-Rs? (Score:3, Insightful)
I've bought nothing but Taiyo Yuden discs for the past 2 years, and have the learned the hard way that they aren't any better. Many discs that I've burned over the past 2 years have become unreadable in as little as 6 months. These discs were stored in jewel cases, in a drawer, and handled carefully (not used as a frisbee or coaster).
I've even tried burning at lower speeds, (i.e., burning at 16x even though the discs are supposed to support 32 or 48x) thinking that mayb
Re:Magneto-Optical? (Score:4, Informative)
However, others have noted that real-life disks can have a much shorter life.
Normally I'd reckon that off-brand disks come off the same production lines as name brands, but Maxell currently has a campaign to warn people that some white disks are digitally marked as Maxell, which can lead to a recorder treating a disk as a 4X when it's actually a 1X. So perhaps one should stick with branded products for archival purposes.
TDK claims to be using a more stable cyanine dye now, which should translate to increased storage life.
As a rule of thumb, disks recordable at higher speeds should have a longer storage life than those limited to 1X, since improvement in dye stability is directly responsible for the increased recording speeds.
Re:God damn it tell me (which CD-R's not to use)! (Score:3, Informative)