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16x DVD-R Drives Planned for 2004
madsenj37 writes "From this article at PC World: 'Mitsubishi Electric has developed a more powerful semiconductor laser that should pave the way for 16X DVD writers to be commercially available by about 2004. The new laser is able to deliver pulses of light at a power of 200 milliwatts, which is double that of lasers used in today's 4X DVD writer drives, the Tokyo company said this week.' It goes on to say that a whole Digital Versatile Disc Could be written in about 3.5 minutes."
@ 20MB/s
Why the discrepency between CD-R and DVD-R drive speeds (i.e. 40x CD-R writes a 640mb disc in ~3.5 min whereas a 16x DVD-R would write a 4.7gb disc in ~3.5 minutes). Anyone?
fp?
...and develop a DVD substrate that won't ignite as lasers move to higher power and lower wavelength.
I hereby patent that idea.
But what do I know. I'm just looking for anonymous gay sex.
Would it be possible to have multiple lasers all burning at once to increase speed? Like dual lasers working on opposite sides of the disk.
Of course, the software logic required to keep the lasers out of each others layers could be complex, but it seems from an ignorant stance that you could immediately double write speed that way. Add three and would you triple?
Anyone that knows more than me have a word on this?
I know the Truespeed CD readers operated on the same basis, only they had 7 reading heads, not writing. I suppose you could do the same with writing heads, but I guess they would be a lot harder to align properly, with much less tolerances. Besides, I don't really think there's that big a marked, if you can't do it within a reasonable time with 16x burning you'll likely to for pressed DVDs anyway. That's why the truespeed drives failed really, if you needed that fast a CD, why not have it on hdd instead...
Kjella
Live today, because you never know what tomorrow brings
First was they were dependent on the spiral pitch being relatively constant so they could hit 7 tracks at once. Well, they were constant until 80 minute CDs came out.
Second is that the tracks on CD-Rs aren't completely parallel. CD-R tracks have a slight wobble to them to allow the writer to determine the rotation rate of the disk (and thus how far they are along) while writing. The wobble is a fixed frequency, and thus as the track lengths change from inside to outside, the wobble does not nest up nicely between tracks like Pringles chips. So, all of a sudden, tracking one track didn't keep the other 6 readers on line.
Finally, they got killed by copy protected CDs. Copy protected CDs purposely have bad sections to them. With most CD drives you read up until you get to the bad spot and then the drive freaks. On a Zen, the drive would freak 6 rotations early. This made it incompatible with copy protections and slowed the read speeds in the protected area.
To be honest, the technology, while neat, had a fatal flaw from the start. On a single head drive, when the disk rotates around once the head is advanced to new data on the next spiral. On the Zen, the head is ONLY advanced one spiral. Thus, 6 of the heads are reading the same spiral that the head next to them read last time around and only one head is reading new data. Thus, you have to get off the spiral, move the head, and then servo lock to the spiral again. And once of the slowest things a CD-drive can do is servo lock to the spiral. This is why seek times are in the 50ms range (used to be 150ms!). So you get data at 7X speed, then have to pick up and move to another spot for 1/20th second, then get data at 7X again. It's no wonder the drives rarely produced the speeds they spoke of.
Maybe a 16X DVD-R drive will settle the war between DVD-R and DVD+R. One can only hope.
http://www.kubuntu.org/
Apples are for people who like their computer to look pretty as opposed to being more useful.
:)
"Useful" is not measured by MHz alone. Frankly I cannot even tell the difference between 1.2GHz and 1.6GHz so really what difference does it make? I'm not looking for geek bragging rights, I can do my software development on a 500Mhz just as easily. The appearence of the computer is even less of an issue to me, I don't know about you, but I do not carry around a picture of my computer in my wallet
I do like having a Unix based operating system with a clean and useful GUI on top of it. In my opinion (yours may vary, this does not make either of us wrong), OS X smokes the hell out of KDE and Gnome. Also it is nice to have Powerpoint (the only componant in Office that is better than the OpenOffice equiviliant, again in my opinion) and PhotoShop (Gimp just isn't there yet, but it will be someday).
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