LSI MegaRAID SCSI 320-2 RAID Controller Series 518 - Manual (Page 22)

1-2 Overview
Copyright © 2002 by LSI Logic Corporation. All rights reserved.
1.2 NVRAM and Flash ROM
A 32 KB x 8 NVRAM stores RAID system configuration information. The
MegaRAID SCSI 320-2 firmware is stored in flash ROM for easy
upgrade.
1.3 SCSI Connectors
The MegaRAID SCSI 320-2 has two ultra high-density 68-pin external
SCSI connectors and two 68-pin internal SCSI connectors for internal
SCSI drives.
1.4 Single-Ended and Differential SCSI Buses
The SCSI standard defines two electrical buses:
•
Single-ended bus
•
Low-voltage differential bus
1.5 Maximum Cable Length for SCSI Standards
Table 1.1 lists the maximum SCSI cable length and number of disk drives
that you can use, depending on the SCSI speeds and type of device.
Table 1.1 Maximum Cable Length for SCSI Standards
Standard
Single Ended
SCSI
Low-Voltage
Differential SCSI
Maximum # of
Drives
Ultra SCSI 1.5 m 12 m 7
Ultra SCSI 3 m 12 m 3
Wide Ultra SCSI 12 m 15
Wide Ultra SCSI 1.5 m 12 m 7
Wide Ultra SCSI 3 m 12 m 3