I still think it is best to read all of the other sections in this area and look at how
IDE/ATA and SCSI compare in various respects. However, I realize that (as usual) I have
made this large by blabbing too much and perhaps some people are looking for a quick
answer. Just recognize that a short answer is rarely as good as a long one.
Overall, the SCSI interface is technologically superior to the IDE/ATA interface. It
supports more devices, allows for better multitasking, more expansion, use of more
high-end devices, more types of devices, and more performance-enhancing features. IDE/ATA
is intended primarily for PCs that are not using a lot of peripherals, or for those that
are cost conscious.
For the average person who is using their PC for light office work, games, internet
use, etc., I still recommend IDE/ATA. The reasons are simple: cost and simplicity.
Virtually all PCs today ship with IDE/ATA hard disks standard, and if you are using a
small number of devices--say one hard disk and one CD-ROM drive, IDE/ATA offers more than
adequate performance for the typical office or home user. As long as the machine is
reasonably modern and the PC is set up properly, IDE/ATA will work without much
difficulty, and there is no need to special-order or customize the machine, since it is
really the "standard". The cost of a simple IDE/ATA setup is far less than an
equivalent SCSI bus.
For the user who is performance-conscious, who will be doing real multitasking, using
many devices at once, doing heavy development work, supporting multiple users at once on
the machine, or who otherwise wants the best and is not afraid if it costs a few hundred
dollars more, SCSI is the obvious choice. SCSI offers the most flexibility, the most
choice of peripherals, and the best performance in a multitasking or multi-user
environment.
So if you are looking to set up a low-end or middling system, I would say SCSI is out
of the question. The simple reason is that for the additional cost of going to SCSI, you
could probably improve overall performance more by buying a faster processor, more system
RAM, or a faster hard disk. For a high-end system, SCSI has definite advantages and is
preferred. It is those who are "in the middle" who might have a tough decision
to make.
Also bear in mind that there are some peripherals that generally are only available on
SCSI, or that have significant enough advantages on SCSI that if you want to use this type
of device, SCSI is pretty much a must. Once you make the decision to go with SCSI, the
cost of going to SCSI for your hard disks is reduced because you've already made the
commitment for the host adapter, which is the large up-front cost of SCSI.
The final, real bottom line is: if you want it cheap and simple with good performance,
use IDE/ATA. If you want maximum performance and flexibility and have the money to pay for
it, use SCSI.
Next: Cost
