Bus Segments On The Hp Ultra3 Scsi Host Adapter - HP D5970A - NetServer - LCII Installation And Configuration Manual

Bus Segments on the HP Ultra3 SCSI Host
Adapter
The HP Ultra3 SCSI host bus adapter features technology that ensures you get
the best performance from your Ultra3 and Ultra2 SCSI devices by
electronically isolating the primary LVD/SE segment from the secondary SE
segment on the SCSI bus. This allows the HP Ultra3 SCSI host bus adapter to
support newer Ultra3 and Ultra2 SCSI devices at speeds up to 160 MBytes/sec
on the primary LVD/SE segment while at the same time supporting Ultra
(legacy) devices at speeds up to 40 MBytes/sec on the secondary SE segment.
The following figure shows the two SCSI segments.
Primary LVD/SE Segment
Figure 1-2. Primary and Secondary Bus Segments
NOTE If you attach Wide Ultra or Ultra SCSI devices to the LVD/SE
connector(s), the data transfer rate for all attached Ultra3 and Ultra2
SCSI devices will drop to Ultra SCSI performance levels. However, if
you attach only Ultra3 and Ultra2 SCSI devices to the LVD/SE
connector(s), data will be transferred at the maximum possible rate
(80 MBytes/sec for Ultra2 devices and 160 MBytes/sec for Ultra3
devices).
2
Secondary LVD/SE Segment
AIC-3860
AIC-7892