In past columns, we've discussed the value of optical disc storage for digital content. We are already accustomed to using optical discs exclusively for distributing content to end users and clients. (I can't remember the last time I used a Zip disk, let alone a floppy, for sending anything—between optical and online, there's no middle ground for distribution these days.) As a result, we are now amassing vast libraries of content on optical disc in our archives.
With CD and DVD jukeboxes, enormous amounts of content (project files, samples, client data, etc.) can be recorded in a central library. All this content remains accessible to both internal and external users without cluttering up our RAID systems. Optical discs thus offer one effective answer to the need for greater storage space at ever-lower costs. The discussion, however, remains open as to how to keep improving access times to that optical media.
For the digital studio—where content is not just accessed, but produced— the access challenge is different than for end-users. For end-users, the argument about drive speeds ended some time ago. Given that most discs only use a third or less of their capacity, the difference in throughput between a 36X or 48X speed CAV drive is nominal, since the drive only reaches top speed at the unused outer edge of the disc. For recording, moving from 8X to 40X Max is significant, but will 48X Max recording be that much better?
For the digital studio, on the other hand, the problem is that not one, but several people want access to data on a disc containing, say, frequently used clip files. One solution is to take a disc manually from the shelf to a local drive, but that's hardly time-efficient or conducive to multi-user access. This age-old network access problem presents enormous headaches for keeping libraries online and current.
A more efficient solution is the aforementioned optical jukebox. By keeping the data in a central location while still putting it out on the network, protecting that content is relatively easy. A jukebox, however, has a finite number of drives. If too many people want access to optical media, the wait begins. So incremental (or better yet, exponential) improvements in drive technology make a world of difference in a multi-seat studio with lots of bulky image and video files in circulation.
The need for capacity makes it high time to move to DVD as the primary optical system of choice. With Pioneer's DVR-104, pricing is no longer the constraint for DVD. Recorders at $240 and dropping have already appeared as of mid-2002. There isn't another worthwhile backup device around that cheap. DVD-R media also is predictably moving downward to under $1. Even with CD-Rs costing pennies, the added capacity and convenience of DVD outweighs the lower cost of CD-R.
One challenge facing DVD is the relatively lower recording speed of the recorders. While 48X CD-R units are cranking out 8.3MB/sec onto disc, users of 2X DVD-R must for now bide their time with 2.6MB/sec. Improved write head technology will move the DVD-R speed upward in drives due later this year. The rotational speed is already there with the CD-R motors—about 11,500RPM worth. The 2X DVD-R is moving at just 2,800RPM, so cranking it up four times should make a significant difference in recording speed.
CD-R drive performance continues to charge ahead. Sony, for example, announced in April of this year, a Digital Signal Processing chipset capable of 60X CD recording. Look for drives with this chipset sometime this fall.
Naturally, with a 60X CD recorder, the disc is going to be really moving—about 14,000RPM or more. Get DVD-R going at that speed (theoretically) and we'll be looking at 13MB/sec—4.7GB in 6 minutes!
So is 60X the limit for CD-R? For one thing, the logic of diminishing returns says yes. Manufacturers will grow increasingly reluctant to devote much more development time to CD-R standalones as writable DVD goes mainstream, and will devote most of their energies to combo drives.
Technically, the pursuit of speed has an upper limit not because of drive motors or read heads. It is the media. Twenty years ago, CD specs were developed for media to function when spinning at a mere 500RPM. Granted, materials have improved since then. But given the mandatory thickness standard, media can only become so strong. So CD/DVD media is reaching its upper limit for durability at 11,500RPMs. After that, things get a little dicey.
How dicey? In one test, researchers subjected CD media to speeds of 27,000RPM, and it disintegrated in a matter of seconds. This speed would correspond to a 110X drive. Providing a large safety margin for contemporary CD/DVD substrate seems then to limit drives to a speed of 60X and under. While properly containing potentially explosive drives might make an interesting column—not to mention satisfy the speed-need—it's bad for business.