UPGRADING REPAIRING PCs

Table 4.14 Other IDE Drive Installation Problems and Solutions
Continued
SCSI 113
Problem Causes Solution
One or both IDE Drives might not Reverse master and slave
drives on a be 100% jumpering; move second drive to
single cable compliant with ATA other IDE connector and jumper
are not standards (very both drives accordingly.
recognized by likely when
system (drives trying to mix
are spinning various brands
and are of IDE drives,
jumpered especially
correctly). older ones).
SCSI
The small computer system interface (SCSI) is a very flexible and
high-performance drive and device interface. In addition to supporting
hard drives, it also can support non-bootable optical and
tape storage, scanners, and many other device types.
SCSI Types and Data Transfer Rates
While many types of SCSI exist, different SCSI types can be mixed
on the same host adapter. For best results, you should buy a host
adapter capable of running your fastest devices at their top speeds
and one that enables various types of devices to run without slowing
each other down. Use Table 4.15 to learn common SCSI types
and their characteristics.
Table 4.15 SCSI Data-Transfer Rates
Bus Standard Fast Fast-20 Fast-40 Fast-80 Cable
Width SCSI SCSI1 (Ultra) 2 (Ultra2) 2 (Ultra3) 2 Type
8-bit
(narrow)
5MB/sec 10MB/sec 20MB/sec 40MB/sec 80MB/sec A (50-pin)
16-bit 10MB/sec 20MB/sec 40MB/sec 80MB/sec 160MB/ P (68-pin)
(wide) sec3 1. SCSI-2
2. SCSI-3
3. Ultra2Wide