How are CD-ROM drives for personal computers rated?
The major statistic used to rate and sell CD-ROM drives is spin speed, usually expressed as a multiple like 52X. What this number actually means is more complicated than you might think.Types of DrivesEarly CD-ROM drives used a system called Constant Linear Velocity, under which the spin speed of the disc would actually change based on what part of it was being read, to ensure that a point near the inside and a point near the outside of the disc would be going at the same speed when they were read. Newer, faster drives use Constant Angular Velocity, which maintains constant disc speed, meaning that the data transfer rate actually changes depending on where you are on the disc.Spin RateThe “X” multiplier refers to the spin rate of a standard audio CD, which is expressed as 1X. Thus, a disc in a 52X CD-ROM drive is spinning at 52 times the rotational speed of an audio CD. Since audio CDs use the CLV system, the 1X spin speed actually varies from about 210 to 539 RPM.What the X Means For
