24x DVD-Rs and 24x DVD+Rs

[dolphinius_rex]

Do people think 24x DVD±R media is possible?

This is a serious question by the way... and I'm looking for serious answers and speculations.

I have received some interesting data, that a certain Taiwanese DVDR manufacturer has begun R&D on 24x DVD±R media... I already know of a DVDR dye type that could handle these speeds, but I was under the impression that speeds of that nature would rip the disc apart due to the centrifical force.

So.... scientfically speaking, can 24x be done?

Cfitz, MediumRare, care to lend your thoughts on this matter? (everyone else is free to as well!).

[RJW]

Scientifically speaking 24x can be done and has been proven on lab scale allready . Infact DVD recordables have a better surviving change as cd-r's thanks to the full bonding which means that cracking will not happen as fast.
However the question is why do it ?

Well the only reason is the speed marketing concept.
In the old days the speed marketing for cd-rom drives was quite important.
However the scattering disc's incidents have partially killed it.
It's not only the speed you also need to proof it's safe and is working good. (Seeing the C't test results and some other stuff that came in today means that 16x isn't really market ready.)
So next your disc needs to be of a even higher manufactureing quality.
Which means even more fall out. So only if you can get people to pay the higher price you got yourself a deal. So this again puts us back at marketing.

Now how much time will you safe. Probally 2 seconds at best.
Why so low ? Well allready the CAV/z-CLV formats need increasing we allready know that.
However at these even higher speeds you have a good change that the calibration time will be even longer killing allmost all the time you won by going faster.

Also there is another thing. Which drive manufacturer will be insane enough to support this? Since you mention it's a taiwanese companny we all know that even if it was a standard product it would take quite some months for the japanese compannies to support it.

The only reason why 24x DVD recordables should exist is for the faster creation of coasters. Still buying your coaster directly is faster but then again you don't have the fun of makeing them. -R. Wilting 13-1-2005.
(Hmm I really like this one might make this my private signature.)

Let me say this if you have any influence tell them they could better spend the money on the development of next generation media our on faster DVD+/-RW's since I have reason to believe that even 16x for these might be possible. Or if they really want to burn money because they want to be inventive tell them to work on Dual Layer Rewritable DVD's.

[dolphinius_rex]

Heh, I like that coaster quote

I'll try to find out more when I can... but it's pretty hush hush right now of course!

but yes, 16x DVD+RWs are also being worked on by this particular Taiwanese based DVD media manufacturer

[CowboySlim]

The rotational forces aren't an issue for me. I take all my fresh media down to Big O Tires and get them spin balanced.

Slim

[vinnie97]

I remember when Kenwood released their multiple laser-based TrueX CD-ROMs that could could read back discs at 72X. I'm surprised no other teams have jumped on this prospect especially with the advent of these larger capacity DVD discs (and now dual layer with blue ray and others on the horizon). Perhaps, it's been deemed as junk science and way too problematic for writing to discs. :|

[dolphinius_rex]

I remember when Kenwood released their multiple laser-based TrueX CD-ROMs that could could read back discs at 72X. I'm surprised no other teams have jumped on this prospect especially with the advent of these larger capacity DVD discs (and now dual layer with blue ray and others on the horizon). Perhaps, it's been deemed as junk science and way too problematic for writing to discs. :|

Well, you know those Kenwood devices were an utter failure... they had very short lifespans, and usually when they died, they took whatever disc was in the drive at the time with them (by method of melting the plastic!). I had a friend who owned one of those drives, and lost a windows 98 CD when his drive finally died. Luckily, he was smart, and only used backups of his discs, and kept the originals in a safe place.

[RJW]

by method of melting the plastic

So it actually is a burner. Well that gives a whole new definition to cd burning.

About the Kenwood drives.
Usseing the technique used in current writers would be very hard to incopperate and I'm sure you don't

First you would have a optical pick up that can send different pieces directly. Unless you go for more real optical pickups. Now this last one would increase the price much since these are probally the most costing thing in the dvd recordable drives.
Reading is one thing (And Kenwood allready proofed that it wasn't that easy. (Specially when it came to audio) ) but burning would be a mayor problem. Next you would need multiple buffers for the different blocks if you want something as brun proof. (And also more advanced technologies like WOPC)
Now the other problem is were to leave the burning heat. I think this drive will need a fan.
So I think that the technology will die a long with the Kenwood drives.

[vinnie97]

Well, you know those Kenwood devices were an utter failure... they had very short lifespans, and usually when they died, they took whatever disc was in the drive at the time with them (by method of melting the plastic!). I had a friend who owned one of those drives, and lost a windows 98 CD when his drive finally died. Luckily, he was smart, and only used backups of his discs, and kept the originals in a safe place.

I had one of these drives and was amazed by the performance before it did die a death less than a year after I purchased it. However, it went out quietly and didn't commit any homicides in the process.

RJW, those are good points, especially about the need for multiple buffers and fans to allay the issue of overheating. Maybe in the distant future this may be possible, but I suspect we'll be using holography for average storage needs by that time.

[RJW]

It's possible but do you want to pay a much higher price and in the end have even worse burning quality ?

[Scour]

Hello!

I think reading at this speed is possible, but you need to make drives like the Kenwood True-X 72 with more than one laser.

Writing can be a problem, i think it´s much more complicated if you had more laser´s

But both things could be to expensive.

[dolphinius_rex]

Hello!

I think reading at this speed is possible, but you need to make drives like the Kenwood True-X 72 with more than one laser.

Writing can be a problem, i think it´s much more complicated if you had more laser´s

But both things could be to expensive.

You could have 2 lasers going... one starts from the inside, and one starts from the outside.... and then they meet halfway through.

[MediumRare]

You could have 2 lasers going... one starts from the inside, and one starts from the outside.... and then they meet halfway through.

LOL

Back to 24x- I'm not into material science much, but basic mechanics says that the angular velocity of a given disc scales linearly with the linear velocity of its rim and that the cetrifugal force goes with square of the velocity.

So going from 16x to 24x increase the RPM's by 50% while the stress on the disc will more than double (2.25). Maybe a laminated disc (DVD) will be stronger than a monolithic one (CD)- I sure wouldn't want to bet my drive on it though.

RJW makes good points. One of problems today, as shown in c't tests for example, is mechanical variations of the raw disc- axial and radial deviations from the ideal case. These become most noticeable toward the outer edge where the disc has the highest (linear) velocity and the dye properties are most crucial. This is also the region of the disc where the dye (usually spin-coated) is subject to the most variations. This compounding of critical properties is why many discs burn better at lower speeds.

This may bound on heresy here at CDRLabs, but personally I would be happy with good quality 8x media for RW (or DL). The difference in burning time between 8x and 16x is only ca. 25%. OK it's nice to go faster if the quality doesn't lose and I've made my share of coasters finding the limits of my drive (which are more acute than most- it's a LiteOn 1213s@1633S) and will continue to do so- but that's for fun and sharing with you guys. My bread-and-butter stuff is @8x.

G

[Scour]

You could have 2 lasers going... one starts from the inside, and one starts from the outside.... and then they meet halfway through.

Uhh, maybe they crash

[dolphinius_rex]

Back to 24x- I'm not into material science much, but basic mechanics says that the angular velocity of a given disc scales linearly with the linear velocity of its rim and that the cetrifugal force goes with square of the velocity.

So going from 16x to 24x increase the RPM's by 50% while the stress on the disc will more than double (2.25). Maybe a laminated disc (DVD) will be stronger than a monolithic one (CD)- I sure wouldn't want to bet my drive on it though.

G

It seems to me that 24x recording is more impracticle then impossible... so I wonder what this company is thinking? Even for marketing purposes it would be problamatic since they'd have to find a drive maker to support it also! (I suppose Artec would do it ). But on the other hand, every other company could start advertising their DVDRs as being "non-explosive media"

[RJW]

I allready said that.
However never underestimate compannies stupidity. Some compannies really need to do R&D themselves to find out that it's not word the time and money even while some others allready prooved it.
They would just say well were better and we have some new idea's even if you know that the orriginal compannies have a 5 time as big research budget and thoroughly tested it.

About double layer vs monolayer.
If a DVD is well bonded (There still turning up batches that are bad bonded from some manufacturers now and then.) DVD's should have a much smaller change of scattering as cd-r's.
Also the DVD-forum chose for full bonding because they wouldn't want to make the next potential murder weapon. (They left that up to SONY with it's ninjastar shooting PSP. )

[cfitz]

Not much for me to add here. I think everyone else has already pointed out the majority of the relevant issues. But there are a few additional points I didn't see in a quick skim:

1. Faster burning requires higher laser power (again = more expensive).

2. Time spent (wasted?) pushing the limits on DVD speed = time not spent developing the next generation of higher density systems like Blu-ray. A company could win the battle for fastest DVD and lose the war for fastest/most dense optical system overall. (Is this what happened to Lite-On in the switch from CD-R to DVD-R?)

3. How many years have we been waiting for the rumored 20x DVD-ROM? Yes, it isn't exactly the same thing, but it illustrates the difference between what could be done and what is worth doing.

cfitz

[Ian]

Sorry I have to throw this in here since it sort of relates. Now I agree with what has been said, but according to Kristopher@Anandtech, you're all wrong. You won't have DVD writing speeds faster than 16x due to "the physical limitation on hard drive read speed".

http://www.anandtech.com/tradeshows/sho ... i=2320&p=4

Of course, if you hadn’t heard it from us before, let us be the first to tell you that 16X will definitely be the fastest single layer write speed possible. As media and drive manufacturers already start setting their eyes on BluRay and HD-DVDR, DVDR will only continue advancements in dual layer capability. Keep in mind that the physical limitation on hard drive read speed is what keeps DVD burners from writing faster than 16X – it’s going to take SATA-II or some other technology to keep up high sustainable IO transfers to redefine optical storage writes (and by that time, we expect to all be burning FVD’s, right?).

Hmm.. let's do some math here. Reading/Writing a DVD at 1x is what? 1385 KBytes/sec? Writing at 16x then is 22160 KBytes/sec or about 22MBytes/sec. No problem for modern hard drives. Bump it up to 20x.. that's 27700 KBytes/sec or ~28MBytes/sec. Still no problem for most hard drives. It's not until you hit 24x (33MB/s) that you start pushing the transfer rates of older or low end drives.

Maybe I'm too hard to Kristopher. Maybe he wrote the article after throwing back a few too many free beers at one of the CES parties. Who knows.. Anand or someone really needs to check his facts though.

[Phoenix '97]

Hmm.. let's do some math here. Reading/Writing a DVD at 1x is what? 1385 KBytes/sec? Writing at 16x then is 22160 KBytes/sec or about 22MBytes/sec. No problem for modern hard drives. Bump it up to 20x.. that's 27700 KBytes/sec or ~28MBytes/sec. Still no problem for most hard drives. It's not until you hit 24x (33MB/s) that you start pushing the transfer rates of older or low end drives.

I bought a 200GB Maxtor hard drive just a few weeks back. 7200 RPM, 8MB buffer. I benchmarked it with HDTach - while it was able to read at about 60MB/sec at the start of the drive, it tapered down to about 30MB/sec at the end of the drive. So even with a modern hard drive, if your data's at the end, or even worse, fragmented, you may get slowed down.

[Ian]

Yeah, I know Phoenix. It's just that there are larger hurdles than hard drive speed.

Shaun also pointed out this comment about LightScribe to me:

The whole process effectively triples the total burn time of the laser during a typical burn – and in the same stride, reduces the average life of the laser by 66%.

I'm sure drive manufacturers are going to love that comment. Kristopher, if you're reading this, where do you get these facts from? The internet? 'Cause we all know everything on the internet is true.

[CowboySlim]

I'm sure drive manufacturers are going to love that comment. Kristopher, if you're reading this, where do you get these facts from? The internet? 'Cause we all know everything on the internet is true.

I heard it from Dan Rather on 60 Minutes so it really, truly has to be a fact. What has more credibility than Dan Rather?

Slim
Who has to get to Phoenix, Tucson, and Nogales as they have some great custom bootmakers there.

[Nil Einne]

While this is offtopic has anyone ever actually experienced or have first hand knowledge of CDs shattering? I know some people claim it has happened and I suspect it has happened once or twice, I wonder how common it is. I've always thought it was more of an urban legend. Especially since a number of times when I read about the so called shattering CD, a lot of people seemed to think it was 56x CAV since these RPM speeds they claimed the drivers were going at were insane (22k or so)

[Ian]

I've had one or two crack, but never shatter.

[dolphinius_rex]

no shattering for me either... but there have been a few times I have been extremely concerned about it because of the noises coming from my LiteON 48125W

[PhotoJim]

Maybe it's time we went back to the caddy ... 24x DVD burning might be pretty safe and easy if we used caddies instead of traditional optical disc trays. However, we all know how well caddies succeeded in the market; they're inconvenient, so users hated them, but they really did make a difference in burning and reading quality and kept the disc more stable and more correctly positioned.

[dolphinius_rex]

Maybe it's time we went back to the caddy ... 24x DVD burning might be pretty safe and easy if we used caddies instead of traditional optical disc trays. However, we all know how well caddies succeeded in the market; they're inconvenient, so users hated them, but they really did make a difference in burning and reading quality and kept the disc more stable and more correctly positioned.

Blu Ray will likely be caddy based