The Different Flavors of SCSI

SCSI-1  Narrow Single Ended:                     5 MB/sec,  8 dev,   6m
SCSI-1  Narrow Differential:                     5 MB/sec,  8 dev,  25m
SCSI-2  Fast Single Ended  :                    10 MB/sec,  8 dev,   3m
SCSI-2  Fast Differential  :                    10 MB/sec,  8 dev,  25m
SCSI-2  Wide Single Ended  :                    10 MB/sec, 16 dev,   3m
SCSI-2  Wide Differential  :                    10 MB/sec, 16 dev,  25m
SCSI-2  Fast/Wide Single Ended:                 20 MB/sec, 16 dev,   3m 
SCSI-2  Fast/Wide Differential:                 20 MB/sec, 16 dev,  25m
SCSI-3  Ultra Single Ended:                     20 MB/sec,  8 dev, 1.5m
SCSI-3  Ultra Differential:                     20 MB/sec,  8 dev,  25m
SCSI-3  Ultra/Wide Single Ended:                40 MB/sec, 16 dev, 1.5m
SCSI-3  Ultra/Wide Differential:                40 MB/sec, 16 dev,  25m
SCSI-3  Ultra/Wide Low-Voltage Differential:    40 MB/sec, 16 dev,  12m
SCSI-3  Ultra-2 Differential:                   40 MB/sec,  8 dev,  25m
SCSI-3  Ultra-2 Low-Voltage Differential:       40 MB/sec,  8 dev,  12m
SCSI-3  Ultra-2/Wide Differential:              80 MB/sec, 16 dev,  25m
SCSI-3  Ultra-2/Wide Low-Voltage Differential:  80 MB/sec, 16 dev,  12m
SCSI-3  Ultra-3 Low-Voltage Differential:      160 MB/sec, 16 dev,  12m