CD-ROM technology approaches a turning point
- By Gerald Lazar
- May 24, 1998
While industry vendors continue to up the ante with CD-ROM drive performance, many users realize they are seeing diminished returns as the technology nears the limits of its performance and new disc solutions enter the market.
The romance of speed always has been part of the PC business; processors, modems and disc drives are priced primarily on how fast they do their jobs. It is no surprise that CD-ROM drives are sold primarily on how quickly they can read data off the disc.
Faster does not always mean better, although in some cases it will.
Although faster drives are still in the pipeline, the market is looking to recordable CD-ROMs (CD-Rs) and Digital Video Disc ROMs (DVD-ROMs), which would make possible new applications, not just more speed.
"The speed of the drive has been driven by the marketing department, not the engineering department," said Jerry McFaul, a computer scientist with the U.S. Geological Survey. McFaul is also president of the Special Interest Group on CD Applications and Technology Foundation (SIGCAT), a nonprofit organization founded to educate the public about CD and DVD technology.
Measure for Measure
These venerable drives— nearing the end of their life cycle after less than a decade— are bought and sold according to how many times faster they are than the original 1X CD-ROM drives, which accessed data at 150 kilobits/sec.
"The performance of CD-ROM drives has come such a long way," McFaul said. But advances these days come in increments, so users could see a big difference going from 2X to 4X "but not between 24X and 32X," he said.
The fastest drives, typically 32X at present, demand twice the price of their next-highest-rated cousins. But that is a triumph of sizzle over steak, observers said. Performance improvements, when they exist at all, rarely match the price differential.
"Buyers have the speed imprinted on their minds," said Chris Gray, senior director of the Microtest Inc. Enterprise Group, a Nashua, N.H.-based company that resells CD-ROM drives in network configurations.
The importance of data transfer rates depends on a number of factors, according to vendors.
In a networked environment, today's latest and greatest may not perform markedly better than a prior generation of drives, Gray said. The speed of a drive is important only because it is the most notable indicator of the current technology, Gray said. "Unfortunately, that's still very important in our industry because we haven't been able to succeed with any sort of education effort."
But that is not to say that the fastest drives are a complete waste of money. "They're the high-performing, high-price, Cadillac model," said Scott Fast, senior product line manager for Micro Design International Inc., Winter Park, Fla.
"You might want to move down from there because of pricing considerations, but even then, buyers should remember that the latest technology has the longest life cycle," Fast said. "I like to assure myself that I am buying the best technology that will last the longest time."
Not only that, but an increase in drive speed can mean improved performance, even though a 32X drive generally is not 33 percent faster than a 24X drive in most applications, observers said.
The benefits accrued from fast CD-ROM drives depend on the applications. Users will benefit from seek times and access times, said Paul Meyhoefer, manager of optical storage products for drive maker Pioneer New Media Technologies Inc. For example, "when doing database searches, the speed can be an issue," Meyhoefer said.
SIGCAT for several years has been issuing a software showcase disc, which provides a dozen or more retrieval engines and a database against which to test them. The retrieval engines have become pretty consistent, but all improve their performance with higher-speed discs, McFaul said.
"But it's an incremental improvement," he added.
The transfer of large files also speeds up with faster drives. If users are just taking data off a disc, it may be worth it to get a really fast drive, said Mary Bourdon, principal analyst with Dataquest, a Gartner Group company in San Jose, Calif.
Nevertheless, for most users working with standard applications, the increase in speed may not show. "You wouldn't notice in most consumer applications," said Tim Meyerhoff, multimedia product manager at Panasonic Computer Peripherals Co., a division of Panasonic Communications & Systems Co., Secaucus, N.J.
Even what many would consider high-end applications are not necessarily speed-sensitive. At NASA's Jet Propulsion Laboratory, where the entire Planetary Science data archive is stored on 600 CD-ROMs and several thousand CD-Rs, speed is just not much of an issue. "We tend to take whatever comes with the machines," said Michael D. Martin, project engineer for the Planetary Data System.
USGS has CD-ROM drives throughout the organization for people to access the large databases that the organization deals with, McFaul said. The installed base runs the gamut from 8X
drives through the newest 32X drives. "From a practical standpoint...24X is perfectly adequate for gorgeous full-screen video," he said. "I am running an 8X drive that gives acceptable video for decent-sized quarter screen.... I have no burning desire to move up.... Though I haven't done any benchmarking in a vigorous fashion, I think with 24X you are getting all the bang for the buck you need."
Measuring a CD-ROM's "transfer rate" is a moot point anyway, industry observers said. The "32" in 32X represents the maximum speed of the drive, while the average transfer rate is usually in the mid-20s for such drives.
The Next Generation
Both mechanical and market limitations are bringing an end to the ever-faster CD-ROM drive. Some drive makers, such as Samsung Electronics Co., have strongly intimated that the 32X drive will be their last. Some have 36X in the works, and a few may be working toward 40X. But that should be about as high as they can go, analysts said.
"There are mechanical limits," said Wolfgang Schlichting, research manager for removable storage at International Data Corp., a Framingham, Mass.-based research firm. "As you spin a disc faster and faster, it starts becoming like a propeller. And if the disc isn't perfectly centered, that puts enormous strains on the motors, can cause vibration and heat...and discs tend to warp slightly when spun very fast. This causes air drag, which again puts much more strain on the motor."
Partly because of the mechanical limitations, vendors have been pushing a related technology— DVD-ROM— for several years, and it is just now beginning to enter the market.
"DVD-ROM is inevitable," said Pioneer's Meyhoefer. Current DVD-ROM drives have speeds of about 2.5X, which is roughly equivalent to a 24X CD-ROM drive.
Vendors are touting DVD-ROM for several reasons, but primarily for the capacity. DVD-ROM drives can store more than 2M of data, which make them appropriate for such data-intensive applications as full-motion video.
Most observers expect DVD-ROM to be adopted eventually, with video training as the application that leads the charge. "But the adoption for business is going to be quite a bit slower than for home," Schlichting said.
McFaul disagrees with that assessment. "It will surprise people how fast it will take off," he said. "Interactive training using DVD will let you have what you have with a VCR, but fully controllable and interactive."
Many expect the "crossover," where more DVD-ROMs ship than CD-ROMs, by the end of 1999 or 2000. Dataquest's Bourdon said the crossover will come later, probably in 2001.
Ironically, because DVD-ROM design is so similar to CD-ROM design, creating a drive is subject to the same mechanical challenges. Once DVD-ROM drives start getting up to 7,000 rpm, users will encounter wobble, warping, heat and all the other problems that plague CD-ROMs today, sources said.
Lazar is a free-lance writer based in Tenafly, N.J.
When CD-ROM is not fast enough
According to some observers, CD-ROM drive performance always will be somewhat disappointing for the average PC user, simply because most people have become used to hard disk drives, which can access data much faster.
Some vendors recommend using a hybrid approach of CD-ROMs and hard disks to boost access time for "performance-sensitive" users. By caching the contents of the CD-ROM to a hard disk, a user can read the data from a "virtual CD" at hard disk speeds. Similarly, regularly used CD data can be read into memory and retrieved from there, providing an even greater performance improvement.