Dell 3 Computer Hardware User Manual


 
26 Overview
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PERC 3/SC has one ultra-high-density 68-pin external connector for the
external storage subsystem and one high-density 68-pin internal connector.
Single-Ended and LVD SCSI Buses
The SCSI standard defines two electrical buses: a single-ended bus and an
LVD bus. PERC 3 supports both standards.
Maximum Cable Length for SCSI Standards
Table 1-1 displays the maximum length of cable that you can use for various
SCSI standards.
SCSI Bus Widths and Maximum Throughput
Table 1-2 displays the SCSI bus widths and maximum throughput for each
of the SCSI standards.
Table 1-1. Maximum Cable Length for SCSI Standards
SCSI Standard Single-ended LVD Maximum # of
Drives
SCSI I 6 m 12 m 7
Fast SCSI 6 m 12 m 7
Fast Wide SCSI 6 m 12 m 15
Ultra SCSI 1.5 m 12 m 7
Ultra SCSI 3 m 12 m 3
Wide Ultra SCSI N/A 12 m 15
Wide Ultra SCSI 1.5 m 12 m 7
Wide Ultra SCSI 3 m 12 m 3
Ultra 2 SCSI N/A 25 m 1
Ultra 2 SCSI N/A 12 m 7
Wide Ultra 2 SCSI N/A 25 m 1
Wide Ultra 2 SCSI N/A 12 m 15