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Topic: CD-R vs DVD-R (Read 11940 times) previous topic - next topic
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CD-R vs DVD-R

Reply #25 –
I'd really like to know the longevity issue as well.

However, after having scoured all known publications, archival organisations and conferences on the subject, there is very little information on DVD archival longevity.

And what one can find, well most of it is conjecture or extrapolation from cd-r studies.

NIST DVD Longevity guidelines list the following potential problems:

- scratching, delamination (label side protection only 5-10 micrometers)
- noxious gases (sulfur attacks silver reflective layer, oxidation is problem as well)
- moisture (polycarbonate absorption)

They don't actually list, but it's implicit in their storage recommendation listing (coold, dark, dry) that the following can be problematic as well:

- temperature (hastens some detoriorative processes)
- uv radiation (can affect dye layer, increase jitter)

NIST has started their own DVD longevity study which should be completed c. Q4/2004 and published hopefully not soon after.

It will be an accelerated media aging test, but it should give us some understanding to the expected longevity of dvd (burned) discs, both DVD-R and DVD+R from various manufacturers.

However, in their initial testing they already noticed that:

A) longevity from one brand to another varies considerably
B) manufacturer claims cannot be trusted
C) Jitter increase may be the main cause of disc degradation
D) Light exposure is a significant contributor to jitter increase
E) For many burns jitter is already out of spec right after the burn

So, as in any data storage, it all depends on data inscription, storage media, handling method and storage space "quality", where quality is a multi-variable equation with some propable unknown variables and some known ones.

regards,
Halcyon

CD-R vs DVD-R

Reply #26 –
Quote
A) longevity from one brand to another varies considerably
Good discs live longer in direct sunlight than crappy discs (like princo) in proper environments...
Quote
E) For many burns jitter is already out of spec right after the burn
This is usually the Princo affect, and has not much to do with the burner.

Besides that, there are not even any Jitter specs, so maybe the funny guys at NIST should read a bit before confusing people any more.

CD-R vs DVD-R

Reply #27 –
Seeing as you guys have been praising that benq drive I was wondering if you had any thoughts on the NEC ND-2500A drive.. cd freaks just reviewed it and said it made the best dvds as they'd tested out of any drive they'd tried

http://www.cdfreaks.com/article/134/1

The review is indepth, there are some issues with it.. most i can live with, plus its nice and cheap at £80 ... and any notion of a drive being able to write real high quality copies like that or the benq or plextor one really appeals.. I've had a 1st (maybe 2nd generation) pioneer drive for a year or so now.. to get playback working ok on normal players i have to use zerodefex dvds and burn at 1x ... hopefully these high rated drives would be fine at 4x and 8x in this regard with their high quality writing abilities..

CD-R vs DVD-R

Reply #28 –
Quote
Besides that, there are not even any Jitter specs, so maybe the funny guys at NIST should read a bit before confusing people any more.

Sure there are jitter limits. Jitter must stay below 8% by DVD specs. Many drives can read DVD data up to ~15% jitter, some already fail at 12%. At 20% the data becomes totally unreadable.

CD-R vs DVD-R

Reply #29 –
Quote
Seeing as you guys have been praising that benq drive I was wondering if you had any thoughts on the NEC ND-2500A drive.. cd freaks just reviewed it and said it made the best dvds as they'd tested out of any drive they'd tried

At least c't hasn't tested it yet, but in the next issue (coming out in over a week), they will test all the latest 8x burners.

CD-R vs DVD-R

Reply #30 –
Ok i'll wait for that then.. if the nec one is at least good if not perfect it'll probably be my next drive just for price alone

has the email replies waiting option gone on HA atm?

CD-R vs DVD-R

Reply #31 –
Quote
ure there are jitter limits. Jitter must stay below 8% by DVD specs. Many drives can read DVD data up to ~15% jitter, some already fail at 12%. At 20% the data becomes totally unreadable.
Grr..... this time, I believed the words of the C'T.... ECMA-337 say 9% as limit, ECMA-338 says 8%.

CD-R vs DVD-R

Reply #32 –
About two weeks ago I readed this test.
DVD-R seems to be more "compatible" between recorders / readers, sensiblely more than DVD+R.

Read an get your own clonclusions:

http://www.cdrinfo.com/Sections/DVDMediaFormats/

:-)

I'm using Fuji DVD-R for archive pourposes now.
Best regards.

b:.

CD-R vs DVD-R

Reply #33 –
Some Fujis are Prodisc now, instead of Taiyo Yuden, so watch out...

CD-R vs DVD-R

Reply #34 –
I think it's hard to find absolutely authoritative information on the issue.

Currently the NIST study is the only one that is done right and wide enough to be trusted.

However, it's still undergoing.

As for being funny, I think they know their shit, show to speak.

Or if anybody disagrees, please give references as to on what points and why you disagree.

CD-R vs DVD-R

Reply #35 –
Quote
As for being funny, I think they know their shit, show to speak.
This is what I thought about the C'T as well till this morning...

CD-R vs DVD-R

Reply #36 –
Quote
DVD-R seems to be more "compatible" between recorders / readers, sensiblely more than DVD+R.

Read an get your own clonclusions:

http://www.cdrinfo.com/Sections/DVDMediaFormats/

I've heard different things here. Some say - is more compatible, others say +.  I'll say that I've never had a problem with any + I've burned with a friends drive.  I've also heard something about changing identifiying bits or something with + that helps make it more compatible?
"You can fight without ever winning, but never win without a fight."  Neil Peart  'Resist'

CD-R vs DVD-R

Reply #37 –
As you can see, the CDRInfo - Test only tested quality DVD-R/W, and did not insult their readers with Princo, so the Princo effect could of course not occur.

People who claim DVD+ were more compatible have different reasons:
- they bought a DVD+ drive (yes, i'm serious)
- they use DVD players where DVD- is blacklisted (there are some Philips players like that)
- They first tried Princo DVD- and then DVD+. Of course, any DVD+ works better than Princo DVD-

Quote
I've also heard something about changing identifiying bits or something with + that helps make it more compatible?
You can make a DVD+ say 'i am a dvd-rom'. This helps if a player blacklists dvd+, or with older players that reject any booktype they don't know.

CD-R vs DVD-R

Reply #39 –
Quote
I've also heard something about changing identifiying bits or something with + that helps make it more compatible?

You are referring to the "Booktype Bit" that some burners allow to set before recording to identify the +R(W) as being a -ROM disc which should improve compatibility.

What's going on right now reminds me of the good ole' days of CD writing getting started ... there were that much compatibility issues that it became quite some kind of philosophy to argue about dye colours and compatibility ...
The name was Plex The Ripper, not Jack The Ripper

CD-R vs DVD-R

Reply #40 –
Quote
What's going on right now reminds me of the good ole' days of CD writing getting started ... there were that much compatibility issues that it became quite some kind of philosophy to argue about dye colours and compatibility ...

Yes.. but DVD writing is already quite old, adoption seems to be slower. And the next formats are already on the horizon... After the copy protection debacle with DVDs, Hollywood wants to bring out some improved stuff as soon as possible 

CD-R vs DVD-R

Reply #41 –
Quote
Quote
Seeing as you guys have been praising that benq drive I was wondering if you had any thoughts on the NEC ND-2500A drive.. cd freaks just reviewed it and said it made the best dvds as they'd tested out of any drive they'd tried

At least c't hasn't tested it yet, but in the next issue (coming out in over a week), they will test all the latest 8x burners.

Has there been any updates on this, when is the latest c't out.. I'm itching to buy and still think the NEC is a good one, be nice to get some more feedback from c't seeing as you guys respect it so much.

CD-R vs DVD-R

Reply #42 –
Quote
Has there been any updates on this, when is the latest c't out.. I'm itching to buy and still think the NEC is a good one, be nice to get some more feedback from c't seeing as you guys respect it so much.

I (as a subscriber) will get it this Saturday. Will post something about it on the weekend.

CD-R vs DVD-R

Reply #43 –
Thanks.. its pay day today  I'll hold off on to see if anything is mentioned.. until then i need to try and chill out on finding new music to buy

Cheers

CD-R vs DVD-R

Reply #44 –
Okay, here are a few results for you.

Best for DVD-R: BenQ DW800A (with -R firmware), LG GSA-4081B, Mitsumi DW-7872TE, NEC ND-2500A, Nu Tech DDW-081, Plextor PX-708A, Teac DV-W58G

Best for DVD+R 4x: BenQ DW800A, HP DVD400i, Philips DVDRW824K, NEC ND-2500A, Pioneer DVR-107D

Best for DVD+R 8x: BenQ DW800A, HP DVD400i

CD-R vs DVD-R

Reply #45 –
Elaborating a bit about NEC ND-2500A in comparison to the BenQ DW-800A:
With DVD-R the BenQ got very good results, but it's not really the BenQ's area (the DVD-R firmware was released just recently and manages only 2.4x so far). The NEC got very good results at 4x. Burning 4x media at 8x yields noticeably worse but still pretty good results. With 4x DVD+R media the BenQ manages good to very good results even at 8x. NEC's quality with +R at 4x is comparable to the BenQ at 8x. It is not a good idea however to burn 4x media at 8x with the NEC (bad results with Taiyo Yuden). It is an equally bad idea to burn 8x DVD+R media at 8x with the NEC (average to bad results with all media). The BenQ delivers good results with all 8x media.

So, to sum it up: With then BenQ you can buy whatever +R media you like and burn it at 8x. You could buy -R media but this doesn't make much sense at the moment, since you can only burn them at 2.4x.
With the NEC ND-2500A you can burn -R and +R at 4x with good to very good results. You can also burn -R at 8x with a slight decline in quality. You shouldn't burn any +R media at 8x, though.

Other results: The BenQ reads DVDs a bit faster than the NEC and has better error correction. It's also quieter with DVDs, although the NEC is very quiet as well. The NEC burns CD-RWs much faster than the BenQ (it takes the BenQ longer to burn a CD-RW than a DVD), error correction with CDs is better with the BenQ (NEC's is still very acceptable but the BenQ really excels in this area), both are quite noisy when reading CDs, the BenQ more so than the NEC.

CD-R vs DVD-R

Reply #46 –
Thanks for the updates.. I was going to check back on here earlier today but i'd not gotten an email saying there was an update to the thread.. also i was in a bit of a rush.. I found an NEC drive locally but they closed at 3pm so i had to rush off.. I've gotten one now and am experimenting with it..

What did c't use to test the quality of the rips!? I thought this testing wasn't entirely accurate, the two sites that i'd seen so far both said that they couldn't ascertain anything with the testing software with certainty.. one site wouldn't even compare between drives and only tested media on the same drive and compared the media..

Anyways finding the drive locally and it being nice and cheap (£80) i just went for it.. its disturbing that they dont recommend 8x burning as i'd read stuff claiming that it was the best performing drive tested so far at pretty much all speeds, all formats..

I have some 8x discs.. I will burn at 8x and see if it plays 

http://www.cdfreaks.com/article/134/1

Highlights:

from there write quality testing here

http://www.cdfreaks.com/article/134/6

"Write quality:

You should first notice that this is not a scientific and professional way to test the discs. But according to our testing done the last two months we could conclude that there is a clear link between the quality reported when scanning the disc and the playability of the disc in different devices."

"K-Probe was designed to work with Lite-On DVD-Writers. So we recommend using a DVD-Writer from Lite-On, in this test we use a Lite-On LDW-411S DVD-Writer, as already said; remember that scans done with a Lite-On DVD-ROM or Lite-On combo drive can?t be compared with the results obtained with a Lite-On DVD-Writer."

"We know Taiyo Yuden as one of the best manufacturers for CD-R discs. And as we could see their DVD+R is just as excellent as their CD-R discs. Our highest recommendations for these discs! Consider the fact that this disc is written at 8x and you will realize that the result is simply excellent."

"for DVD-R and DVD+R discs it simply outclasses all the other drives we have reviewed."


http://www.cdrinfo.com/Sections/Articles/S...D2500A&Series=0

Which doesn't talking about writing till page 9..

http://www.cdrinfo.com/Sections/Articles/S...eries=0&index=8

CDs:
"Looking at the graph above, we can see that the NEC drive performed well within limits, where at all speeds the jitter was well below the Red Book limit. These are amongst the best Pit Jitter measurements we have seen from any drive."

"Judging from the results presented on this page, the NEC ND-2500A has proved one of the best CD recorders with regard to quality that we have tested. The jitter levels with Taiyo Yudon media are very low for all speeds. The results on the following pages will show exactly how good a recorder the NEC drive is."

Page 13 for DVDs

"The software used for the measurements was KProbe v1.1.28, the ECC was set to 8 and the reading drive was the LiteOn LDW-811s. The specific methodology is very dependent on the drive used as a reader, while the reliability of the PI/PO provided output is also not technically confirmed. Hence as a result, we cannot safely come up with conclusive results, although we do make a comparison of the drive's behaviour when using various DVD recordable/rewritable media."

"Plextor 4x DVD+R (recorded at 8x), Taiyo Yuden 4x DVD-R (recorded at 8x), Ritek 4x DVD-R media were a little better. The other brands are all acceptable with the best media being CMC Magnetics 8x DVD+R and Mitshubishi Chemicals 4x DVD-RW."

"In the DVD recording tests we would like to congratulate NEC regarding the drive's compatibility with all the media we tested. It managed to burn at the speed of 8x most of our 4x DVD media. Also the DVD writing quality was very good, with low PI/PO levels"

Could you guys confirm what tests c't based their assessements on and how they justify being able to compare drives when cdrinfo doesn't seem to think this is possible..

Just curious really.. hopefully this will be better than my last drive.. the speed and compatibility is what i wanted.. I'll report back when i find out more... for now just gotta test this 4x +RW disk i burnt..

Cheers

CD-R vs DVD-R

Reply #47 –
c't doesn't do the quality tests in their own lab. They send the burned DVDs to AudioDev, where they are analyzed with a CATS hardware analyzer. This method is much more precise than any analyzing you can do on the PC.

I uploaded some of the results for you. This is only a fraction of what the article covers. By any means i advertise buying the c't if you are interested in such tests.

CD-R vs DVD-R

Reply #48 –
Thanks..

I guess thats fairly conclusive then.. is there any other comparisons of other drives.. does the NEC drive sit above any other drives like the pioneer's or Sonys!?

It does make me a bit deflated but unless i see real problems with it i guess i wont notice.. I'm not having too much faith in being able to preserve data on dvds or cds, its just an extra backup incase my harddisks go south again.. beyond that are simple dvd video authoring from my video camera, along with moving tv recordings off my pvr PC onto dvd to be watched on normal tvs..

the 4x +rw burn seems ok.. i'll try some other media and an 8x burn.. it'll make a big difference compared to 1x even at 4x, but i'm hoping that discs play at 8x.. we'll see

Cheers.. i'd like the detail of c't but sadly my german aint good enough to really get anything from it

CD-R vs DVD-R

Reply #49 –
Quote
is there any other comparisons of other drives.. does the NEC drive sit above any other drives like the pioneer's or Sonys!?

The NEC is by no means a bad drive. With -R at 4x its quality is outstanding. There's hardly any other drive which delivers similarly good results (the LG GSA-4081B is about equally good, the Plextor PX-708A and the Teac DV-W58G come close, the Pioneer DVR-107D is OK with Maxell and Taiyo Yuden but messes up with Verbatim). The results at 8x with 4x -R media are still good but worse than the 4x burns with LG, Mitsumi, Nu Tech, Pioneer, Plextor, and Teac. They are however still better than for example MSI's, Sony's or Waitec's results at 4x (the Sony's results are almost all terrible, btw).
NEC's 8x results might of course get even better once 8x -R media are available. The Pioneer was not tested at 8x with 4x -R media, btw, because it won't allow to burn at higher speeds than the media was specified for.