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Single ended and differential scsi buses, Maximum cable length for scsi standards – LSI MegaRAID Express 500 User Manual

Page 16

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MegaRAID Express 500 Hardware Guide

2

Single Ended and Differential SCSI Buses

The SCSI standard defines two electrical buses:

• a single ended bus

• low-voltage differential bus

Maximum Cable Length for SCSI Standards

Standard

Single ended

LVD

Maximum Number 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

12 m

15

Wide Ultra SCSI

1.5 m

12 m

7

Wide Ultra SCSI

3 m

12 m

3

Ultra 2 SCSI

25 m

1

Ultra 2 SCSI

12 m

7

Wide Ultra 2 SCSI

25 m

1

Wide Ultra 2 SCSI

12 m

15

Ultra3 SCSI

25m

1

Ultra3 SCSI

12m

7

Wide Ultra3 SCSI

25m

1

Wide Ultra3 SCSI

12m

15

SCSI Bus Widths and Maximum Throughput

SCSI Standard

SCSI Bus Width

SCSI Throughput

SCSI I

8 bits

5 MB/s

Fast SCSI

8 bits

10 MB/s

Fast Wide SCSI

16 bits

20 MB/s

Ultra SCSI

8 bits

20 MB/s

Wide Ultra SCSI

16 bits

40 MB/s

Ultra 2 SCSI

8 bits

40 MB/s

Wide Ultra 2 SCSI

16 bits

80 MB/s

Ultra3 SCSI

8 bits

80 MB/s

Wide Ultra3 SCSI

16 bits

160 MB/s