There is a prevalent opinion among the experts that it is better to use SCSI in graphic system, servers and computers processing large volumes of data. There are the following types of SCSI: Wide SCSI, Ultra Wide SCSI and others, different in terms of data width and types of connector.
So what’s better, SCSI IDE/Ultra ATA?
I doubt that anyone can give an unambiguous answer to this question. Every interface has its own filed of application. For instance, with the help of SCSI adapters you can connect a large number of devices to one channel (7 or 15 devices per channel, whilst only two per channel via IDE/ATAPI), but does the simple user really need it that often? How often do we have more than 2 hard drives on our PC? Besides that, every motherboard has inbuilt IDE controller a priori, while you need to purchase the SCSI adapter additionally. Of course, there are motherboards with inbuilt SCSI controller, yet their price is much higher.
SCSI standard hard drives cost much higher than IDE drives. However even the most rapid IDE storage devices work way slower than SCSI and their fault-tolerance is indeed inferior. From the very beginning the SCSI devices have been developed to work on server where faultless performance and data integrity are the most important factors of work. And as we have discussed above, on top of all SCSI supports not only storage devices but also professional periphery and, first of all, professional scanners, plotters and other devices.
Nevertheless, it is still better to use IDE for office purposes since it is cheaper and simpler in terms of setting up.