In the previous article we examined five of the fastest ATAPI CD-ROM drives around, ultimately crowning Kenwood's 72X drive with our Editor's Choice Award. Today we look at some of the top SCSI CD-ROM drives available. With speeds ranging from 40X to 52X, and an average street price of $112.75, how will these drives compare to the ATAPI units, which ranged from 48X to 72X and averaged $68.40?
Before delving into our SCSI comparison, let's take a moment to examine some key differences between SCSI and ATAPI CD-ROM drives and how you might determine which is more appropriate for you. First and most obvious is the interface. Nearly all SCSI CD-ROM drives use a standard 50-pin connection. As of today, there is only one SCSI CD-ROM drive that uses a 68-pin Ultra Wide connection-Plextor's 40X Wide, which is included in this roundup. ATAPI drives, on the other hand, use the standard 40-pin IDE interface integrated into every modern-day motherboard. While an ATAPI drive seems the easiest, most logical choice, there are potential limitations. Most motherboards only have two IDE connectors. Each connector can have at most two devices attached. Only one device per connector can be active at a time. So there crops up two limitations-the amount of IDE/ATAPI devices you may use and possible performance degradation when maxing the interface out. The SCSI interface is much more flexible in both regards. A standard SCSI bus can handle up to 7 devices, while a wide SCSI bus can accept 15 devices. All this with only one IRQ taken, as opposed to one IRQ for each of the motherboard IDE connectors, plus an additional IRQ for each add-in PCI IDE controller card you choose to add. Additionally, SCSI devices can be accessed (in effect) simultaneously, losing little to no performance as devices are added to the chain.
The second key difference between SCSI and ATAPI CD-ROM drives is cost. As you may have noticed in the first paragraph, the average cost of the four tested SCSI drives is nearly twice that of the ATAPI drives tested, with lower average speed ratings. The reasons for this are somewhat similar to the reasons SCSI hard drives cost more than ATA hard drives. Mainly, SCSI sells at a lower volume than ATAPI. High volume usually equates to lower cost. SCSI requires the purchase of a host adapter or a more expensive motherboard with SCSI connections built in (additional cost above and beyond the extra cost of the drive itself). ATAPI drives, however, will work in any modern motherboard. Which is most likely to be purchased? ATAPI is the type that is most easily integrated into the vast majority of systems.
While there are other differences, these are the most important to the consumer. It can be concluded that ATAPI CD-ROM drives sacrifice a degree of flexibility and potentially some performance (in maxed-out configurations) for a much lower cost. Conversely, SCSI CD-ROM drives sacrifice cost for increased flexibility in configuration. Which is most important is entirely dependent on the individual and their needs. With that, let us proceed to our SCSI CD-ROM drive competitors!