SCSI, IDE or Extended IDE—it is your choice, so don't get mixed up

Choosing between SCSI and IDE or Extended IDE can sometimes be a tough task.


If you run many low-end PCs for standard office tasks or networked operation and
connect only hard drives and CD-ROM drives via IDE or EIDE, SCSI doesn’t offer enough
performance advantage to compensate for its higher costs or more complex installation
problems.


But if you need top performance, are running a multitasking environment or need to
connect multiple devices, SCSI is the way to go.


Use of a scanner used to virtually mandate SCSI—scanners were only available with
a SCSI or proprietary interface card. Today you can get fast performance from a scanner
attached to your parallel port. Plug a SCSI adapter into the device’s parallel port
connection, and it’s an inexpensive, easily installed SCSI connection.


With MS-DOS and Microsoft Windows 3.x, which still reside on about half of government
PCs, everything works sequentially. Because they don’t allow multitasking, most of
SCSI’s advantages are lost.


Although initial setup with SCSI is more complex than with IDE, adding more devices to
a SCSI bus is usually easy.


But the whole issue of SCSI vs. parallel ports may be rendered moot by the Universal
Serial Bus.


USB promises to connect up to 127 devices to a single port.


The USB interface is in its infancy, but PC buyers should look for USB capability with
future expansion in mind. For now, however, you need to choose between some version of
SCSI and some flavor of IDE to connect your hard drive, CD-ROM, CD-recordable and tape
backup drives.


Combining IDE and SCSI devices on the same PC is possible if you have no other choice.


But my advice is: Don’t go there. 


John McCormick, a free-lance writer and computer consultant, has been working with
computers since the early 1960s.

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