The first consideration in choosing a CD-ROM drive is whether to buy a DVD-ROM drive instead. If price is important—as it may be if you are replacing a failed drive in an older system or building a new system on a tight budget—you can save $25 or so by using a CD-ROM drive. In those situations, consider the following issues:
For most applications, DTR is the most important performance characteristic of a CD-ROM drive. DTR is most important if you use the drive mainly for sequential data transfer, such as playing games or loading software. Unless you have unusual needs, any name-brand $25 ATAPI 40X or faster drive is more than sufficient for anything you need to do.
Average access time is important if you use the drive mainly for random access, such as searching databases. Although access time and DTR are not inextricably related—it is possible to build a drive with a fast actuator and a slow motor or vice versa—there is a fair degree of correlation. Typical inexpensive ATAPI drives may provide true 100 to 200 ms average access (although they are often marketed with inflated average access performance numbers), while high-end drives, particularly SCSI drives, may provide true 85 ms access. If you use databases heavily, go with a high-end drive for its improved average access. Otherwise, a typical ATAPI drive will do the job.
Currently available drives have buffers ranging from 64 KB to 512 KB or more. All other things being ...