OT: CD versus DVD durability?

I've been using recordable CDs to archive data for a long time. My experience has been that they're very robust. I've burnt hundreds of
them (all good brands like Verbatim, Fujifilm and Sony) and have never had a problem with one (unlike floppies, hard drives, Jaz drives and other storage systems). The oldest CDs are now ten years old.
Thing is, I could really do with more capacity on a single disc. But I need the long lifetime. Does anyone know if recordable DVDs are as durable? DVDs are the only alternative for me, because I already have the DVD recorder, and I'm feeling cheap. Can someone give me an authoritative answer, or point me in the direction of a book or website that does?
Best wishes,
Chris
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On May 13, 8:08pm, Christopher Tidy . Can someone give me an

I have copied music CD's so as to have copies in more than one place. And mostly used CD's manufactured by Ritek ( sold by Fry's as GQ). My results have not been all that good. No big deal to me as I just make another copy from the original.
But do a search on Taiyo Yuden. From what I have read at various website they are one of the best blank manufacturers.
Dan
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On 5/13/2011 7:24 PM, snipped-for-privacy@krl.org wrote:

I've burned hundreds of these TY DVDs, maybe 2 or 3 coasters.
<http://www.supermediastore.com/product/u/taiyo-yuden-16x-dvd-r-media-value-line-100pk
David
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On 5/13/2011 7:24 PM, snipped-for-privacy@krl.org wrote:

I've burned hundreds of these TY DVDs, maybe 2 or 3 coasters.
<http://www.supermediastore.com/product/u/taiyo-yuden-16x-dvd-r-media-value-line-100pk
David
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On 5/13/2011 7:24 PM, snipped-for-privacy@krl.org wrote:

I've burned hundreds of these TY DVDs, maybe 2 or 3 coasters.
<http://www.supermediastore.com/product/u/taiyo-yuden-16x-dvd-r-media-value-line-100pk
David
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wrote:

'They' say Taiyo Yuden is the best: http://www.cdrdvdrmedia.com/taiyo-yuden-blank-dvd-r-media.html
The ID code is "TY". I haven't found them locally to try.
I test one disc from each spindle I buy with Nero, and usually burn at half the rated speed.
Maxell and Imation didn't test very good a few years ago. MBI (Moser Baer India) worked better for me than reports suggested they would.
jsw
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Christopher Tidy wrote:

I can't answer that with any authority other than I've been using DVDs for backup for 5 or 6 years. Then seem to be holding up ok.
Having said that, it's important to note the difference in construction between CDs and DVDs. THey may look the same, but they aren't. Not by a country mile.
DVDs are two layers laminated together while CDs are a single piece of plastic,
here is a quicky... http://e-articles.info/e/a/title/DVD-Construction-and-Technology / (except the tracks don't "spiral")
Quick... How many grooves are there on an old fashioned LP record?
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Richard Lamb
http://www.home.earthlink.net/~cavelamb
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On 5/13/2011 11:29 PM, "<<<__ Bb __>>>" wrote:

On each side ...
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Stormin Mormon wrote:

Some records had each item on its own grove so it would only play one song or item at a time.
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You can't fix stupid. You can't even put a Band-Aid on it, because it's
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On 5/15/2011 6:01 PM, Michael A. Terrell wrote:

Then there were the binaural records, two interleafed mono tracks, separate needles for each...called "two-needle binaural reproducers" by Atlantic Records back in 1953.
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<:3 )~

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Close but no bananas as they say.
DVD's are single and can - read the CAN be dual.
I buy DVD's and DVD-DL or dual layer.
Commercial made movie dvd's are typically two and are mechanically attached.
Dual layer DL - disks are pre-made and use two colors for reading each layer while seeing only 1 physical and two colors writing the data out.
I also have BL Blue layer - and it seems to be a single layer at this time.
Martin
On 5/13/2011 10:22 PM, CaveLamb wrote:

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I beg to differ, Martin.
DUAL layer refers to dual recording layers, not basic disc construction. ALL DvDs are laminated construction...
Martin Eastburn wrote:

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Richard Lamb
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I burn DL dual layers in the living room. I don't press them. It is one color inside to outside - I want to say a blue and then red. The other is the other color. Not all dvd players can play them. Not all dvd writers can read or write them. They are expensive and special. These are dual logical layers.
Production ones are dual often and are pressed that way. Production is the dual physical layers.
Martin
On 5/13/2011 11:02 PM, CaveLamb wrote:

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Here's a bunch of Dual Layer info:
http://en.wikipedia.org/wiki/Dual_layer_dvd
Erik
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DISC CONSTRUCTION AND MANUFACTURING
DVD-R and DVD+R discs can be either single or double-sided. A single-sided (SS) disc is composed of a recording side and a dummy side while a double-sided (DS) disc consists of two recording sides. The recording side of a DVD-R and DVD+R disc is a sandwich of a number of layers. First comes a polycarbonate plastic substrate containing a shallow spiral groove extending from the inside to the outside diameter of the disc. A DVD-R disc additionally includes pits and lands on the areas between the coils of the groove (land pre-pits). Added to this substrate is an organic dye recording layer (azo, cyanine, dipyrromethene or others) followed by a metal reflective layer (silver, silver alloy, gold). The dummy side of a single-sided disc consists of an additional flat polycarbonate plastic substrate (sometimes with an additional metal layer to obscure the bonding layer from view for aesthetic purposes). An adhesive then bonds two recording sides (for a double-sided) or a recording and dummy side (for a single-sided) together into the final disc. Some single-sided discs are also topped on the dummy side with decorations or additional layers that provide surfaces suitable for labeling by inkjet, thermal transfer or re-transfer printers.
How are DVD-R and DVD+R discs made? The first step in manufacturing a DVD-R or DVD+R disc is to fabricate the polycarbonate plastic substrates (incorporating the spiral groove and land pre-pits) using an injection molding process. The dye is then applied using spin coating and the metal layers by means of DC sputtering. After both sides of the disc are completed they are bonded together using a hot melt, UV cationic or free radical process. Additional decoration or printable layers are typically applied using screen printing methods. A DVD-R (General) disc undergoes a further manufacturing step in which a specialized computer DVD recorder is used to prewrite information in the Control Data Zone of its Lead-in Area to inhibit direct copying of prerecorded DVD-Video discs encrypted with the Content Scrambling System (CSS). Apart from this, and some minor differences in the configuration of the molding stamper used to create the substrates, the process for manufacturing DVD-R and DVD+R discs is virtually identical.
What is the construction of DVD-RW, DVD+RW and DVD-RAM discs? To allow information to not only be written but also re-written many times over, DVD-RW, DVD+RW and DVD-RAM (rewritable) disc construction is more complex than that of DVD-R and DVD+R (recordable). Just like a recordable disc, a rewritable disc can be either single or double-sided. The recording side of a rewritable disc also uses multiple layers beginning with a polycarbonate plastic substrate containing a shallow spiral groove extending from the inside to the outside diameter of the disc. A DVD-RW disc additionally includes pits and lands on the areas between the coils of the groove (land pre-pits) and a DVD-RAM disc also inside the groove itself (land and groove). Next comes a dielectric layer (zinc sulfide and silicon dioxide), followed by a phase-change alloy recording layer (either indium, silver, tellurium and antimony or germanium, tellurium and antimony), another dielectric layer and a metal reflective layer (silver, silver alloy, aluminum). Additional layers may also be incorporated above or below the dielectric layers (germanium nitride, silicon carbide, silicon dioxide, silicon nitride, zinc sulfide, antimony telluride and others). The dummy side consists of a flat polycarbonate plastic substrate sometimes with an additional metal layer. An adhesive then bonds the sides together into a single disc. The exterior of the recording side may also be hard coated with a transparent material (indium tin oxide, silicon-based lacquer and others) designed to repel dust and resist fingerprints and scratches. Similar to a barcode in appearance, a DVD-RAM or DVD-RW disc can also contain near its inner diameter an optional Burst Cutting Area (BCA) or Narrow Burst Cutting Area (NBCA) to supply information required to implement Content Protection for Recordable Media (CPRM).
How are DVD-RW, DVD+RW and DVD-RAM discs made? As with DVD-R and DVD+R, producing DVD-RW, DVD+RW or DVD-RAM discs involves using multiple manufacturing stages. The first step is to fabricate the substrates (incorporating the spiral groove, land pre-pits and embossed areas) by injection molding. The dielectric layers, phase-change recording, reflective and any additional layers are applied to the substrate using DC, RF and reactive sputtering. After both sides of the disc are completed they are bonded together using a hot melt, UV cationic or free radical process. Since the sputtering process lays down the phase-change alloy in its amorphous condition a special device using powerful lasers (initializer) returns the recording layer back to its crystalline state. Subsequent recording then results in less reflective (dark) areas being written against a more reflective (bright) background. The Burst Cutting Area (BCA) or Narrow Burst Cutting Area (NBCA) is marked into the disc using the initializer or a dedicated device outfitted with a YAG (yttrium aluminum garnet) laser. Hard coating can be applied to the substrates at different stages in disc manufacturing using a variety of processes such as spin coating, vacuum deposition and screen printing. A DVD-RAM disc can optionally undergo a further manufacturing step in which it is physically formatted by a conventional computer recorder (to detect and map any defective sectors). Apart from some minor differences in the configuration of the molding stamper used to create the substrates the process for manufacturing DVD-RW and DVD+RW discs is virtually identical while DVD-RAM fabrication is more involved.
How does writable DVD and CD disc manufacturing differ? Apart from the thinner substrates and tighter manufacturing tolerances, the most significant difference between writable DVD and CD manufacturing is the need to perfectly bond two DVD halves together to create a disc that is the same thickness as a CD (1.2 mm). It is imperative that the two disc halves have the same long-term mechanical behavior to ensure that the resulting disc maintains its thermo-mechanical stability. This is particularly important for high-speed discs where flatness and uniformity are paramount. Writable DVD disc manufacturing equipment and production steps (with the addition of the bonding stage) closely resemble those used to fabricate their CD counterparts. In fact, many media manufacturers have simply modified their existing CD-R and CD-RW equipment to produce writable DVD discs although it is generally expected to become less feasible to do so (for productivity and product quality demands) as the technology and business evolves.
http://www.osta.org/technology/dvdqa/dvdqa13.htm
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Stormin Mormon wrote:

Uphill, downhill or both?
--
You can't fix stupid. You can't even put a Band-Aid on it, because it's
Teflon coated.
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One thing to keep in mind about CD's and CDR's is that the actual data layer, either dye or pressed) is under the label... often only protected by a little paint and/or a coat of lacquer. A small scratch or ding to the label side can spell disaster.
With DVD's (all varieties that I'm aware of anyway) the data layer/s are sandwiched between two layers of Polycarbonate.
As far as writing DVD's goes, the dye layer/s are, and other than size, work about the same CD's. Store them in a cool dark place.
In my personal experience, software that allows multiple burn sessions are often unreliable disappointments, as are 'RW' re-writable type discs.
Back in the 'old days' when all this disc burning jazz started, it was black magic to find blanks that would work with any particular burner... seemingly everything was critical. Burner Mfg and specs, blank dye layer chemistry, rated and actual burn speed/s and of course, outer planet alignment. Lots of coasters were produced.
Then, and for all I know now, there were only a hand full of companies actually producing blank CD's and DVD's, even though they sold under many brand names. Many considered those actually made by Taiyo Yuden to be by far the best. I've never seen a blank that actually sports TY's name or logo.
http://en.wikipedia.org/wiki/Taiyo_Yuden
But as time goes on, it seems like pretty much all blanks work well now.
I used to have a ton of links related to burning... I went through burn bookmark folder, and included the 7 links that still work... not that many, but enough to keep you busy for a while. Note most of these are long in the tooth. See below.
To dispose of discs containing sensitive data, chop them up with sheet metal shears. Be careful if you decide to break them... they can really cut you. In that case, put them in a thickish section of newspaper or a magazine, break them, then just toss the whole mess.
OT: I used to back up my computer to CDR's, then later DVD+R's, but since USB flash drives matured, I've used them. I have two... one that fits nicely in my cell phone case, and another I keep over at a well trusted neighbors house... I update them both every month to 6 weeks. (Yea, I know about portable hard drives, but I'm stuck in my ways, and they work well for me.)
http://www.macdisk.com/isoen.php3
http://www.mscience.com/survey.html
http://www.cdmediaworld.com/hardware/cdrom/cd_utils_2.shtml
http://www.tc.umn.edu/~erick205/Papers/paper.html
http://users.forthnet.gr/ath/axatis/FAQs/CDR /
http://www.cdrfaq.org /
http://www.clir.org/pubs/reports/pub121/contents.html
Erik
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Erik wrote:

A couple of things.
I'd fully agree with what Eric said about R/W and would add "multi session" disks too. They have never really been reliable for me.
Looking in my back-up book (several 256 disk pocket folders) my backup stack goes back to 1998. All of these are still readable.
I had a problem 5 or 6 years back with a DRIVE that didn't make good disks. (and didn't admit it!)
But once a disc is readable, baring scratches, heat, flex, and "friends" they seem to keep going like the Energizer Bunny.
I think the books are probably not the best storage mechanism for really long term archival. Probably best for that would be individual CD cases. But the books are just too handy to dump and that many CD cases would be expensive and take a lot more storage space.
YMMV, as they say...
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Richard Lamb
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<snip>

I would NEVER use USB flash for backup. I've seen way too many USB drives suddenly go bad. In my experience, they are only slightly better than floppies. They are probably better now than they once were, but I only use them to move data around. If data is worth backing up, it's worth backing up onto something reliable.
On the original topic, for CD's I always used Mitsui gold disks. They are now sold under the name "MAM-A". They were touted as the best for many years, and I've never had a problem. They also make DVD's, and are considered by conservationists & archivists as the most stable disks around.
http://www.conservationresources.com/Main/section_6/section6_12.htm
Doug White
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