Intel SRCU31, User Manual

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Getting Started 31
Low Voltage Differential (LVD) Support
The Intel RAID Controller SRCU31 supports Ultra-2 LVD SCSI operating at up to 80MB/sec and
Ultra160 LVD SCSI operating at up to 160MB/sec.
Table 7. Supported SCSI Hard Disk Drive Standards
Maximum Cable Length
(meters)
(1)
SCSI Drive
Standard
Speed
(MB/Sec)
Bus Width
(Bits)
SE
LVD
Adapter Maximum
Devices per SCSI
Channel
SCSI-1
(2)
5 8 6 NA
(3)
8
Fast SCSI
(2)
10 8 3 NA
(3)
8
Fast Wide SCSI 20 16 3 NA
(3)
16
Ultra SCSI
(2)
20 8 1.5 NA
(3)
8
Ultra SCSI
(2)
20 8 3 NA 4
Wide Ultra SCSI 40 16 NA NA
(3)
16
Wide Ultra SCSI 40 16 1.5 NA 8
Wide Ultra SCSI 40 16 3 NA 4
Ultra2 SCSI
(2, 4)
40 8 NA
(4)
12 8
Wide Ultra2
(4)
80 16 NA
(4)
12 16
Ultra160 (Ultra3) 160 16 NA
(4)
12 16
NOTES:
1. May be exceeded in Point-to-Point and engineered specific applications.
2. Use of the word “Narrow,” preceding SCSI, Ultra SCSI, or Ultra2 SCSI (for example, Narrow SCSI) is
optional.
3. LVD was not defined in the original SCSI standards for this speed. If all devices on the bus support LVD,
then 12-meters operation is possible at this speed. However, if any device on the bus is single-ended
only, then the entire bus switches to single-ended mode and the distances in the single-ended column
apply.
4. Single-ended is not defined for speeds beyond Ultra.
5. After Ultra2, all new speeds are wide only.
The preceding information is based on the “STA-Endorsed Terms & Terminology for SCSI Parallel
Interface Technology” specification published by the SCSI Trade Association. It can be viewed at:
http//www.scsita.org/terms/scsiterms.html
SCSI Connectors
The Intel RAID Controller SRCU31 includes two internal SCSI-3 Ultra Wide 68-pin connectors
and two external VHDCI (Very High Density Connector Interface) 68-pin connectors. Each
connector can be fully populated with up to 15 SCSI devices (not to exceed an additive total of
15 devices per channel when using both he internal and external connector for the channel) as long
as cable length limitations for each segment are not exceeded.