The "X" refers to the speed multiple of a baseline CD-ROM drive. A few years back, the fastest CD-ROM drives typically ran at 4X or 8X speeds.
The fastest CD-ROM drives currently on the market run at 40X. AOpen has already completed its 44X CD-ROM drive, for instance, while Acer Peripherals is ready to manufacture 48x CD-ROM drives. Behavior claims to be working on a 60X drive.
The need for more speed comes because these companies want to squeeze out more drive sales before CD-ROM goes away. CD-ROMs will begin to disappear by the turn of the century as electronics manufacturers and PC vendors transition to DVD.
DVD stands as a superior storage medium because, among other reasons, discs hold up to 4.7GB of data. CD-ROMs top out at 640MB, or about one-eighth the capacity of a DVD drive.
"The limitation isn't the speed. It's the capacity," said Jae Kim, an analyst with Paul Kagan & Associates. "Most of the major consumer electronics vendors have said that they will stop making CD-ROMs past the year 2000."
Ironically, the most noticeable difference, however, may come in marketing hype. Although these CD-ROM drives will run at 50X and more, PC users really don't see appreciable differences in CD-ROM drives after 24X or even 8X, according to some analysts.
The Commercial Times reports that some of the companies have said that higher speeds make products easier to market.