CertiGuide to A+ (Core Hardware)  9  Chapter 0110:  Removable Media       9  IV  CD-ROM            9  CD-ROM / CD-RW Interfaces

CD-ROM / CD-RW Interfaces 1 USB & IEEE-1394

A second interface used for connecting a CD-ROM to PC is the SCSI interface. SCSI CD-ROM drives have much higher performance than their ATAPI competitors, but are less common due to the substantially higher cost of SCSI technology.

As you learned in Chapter 0101, devices on the SCSI chain are controlled completely by the SCSI adapter.

Therefore, when performing operations that require a read from one device with a simultaneous write to another device, SCSI outshines IDE.

This becomes even more critical when using a CD-RW device that requires the uninterrupted data flow from the source of the data (a hard disk or another CD-ROM drive) to the CD-RW.

What this means is that if you're using an IDE/ATAPI CD-RW, you are forced to not perform any other operations or run any programs during the burn operation.

However if you're using a SCSI CD-RW, the data transfer is completely controlled by the SCSI adapter and in turn frees up the rest of the system to do other things.

CD-ROM / CD-RW Interfaces 1 USB & IEEE-1394