Dell Precision 410 User Manual page 101

This chapter provides instructions for installing drivers for the following SCSI
controllers:
Integrated Adaptec 7890 Ultra2/Wide low voltage differential (LVD) small com-
puter system interface (SCSI) controller. This primary controller provides transfer
rates of up to 80 megabytes per second (MB/sec) with LVD hard-disk drives and
up to 40 MB/sec with non-LVD hard-disk drives. The chassis supports up to four
hard-disk drives of either type or a mix of both types.
Adaptec 7880 Ultra/Wide external and narrow internal SCSI controller. This sec-
ondary controller provides transfer rates of up to 40 MB/sec and is used for
removable media devices such as CD-ROM drives and tape drives. This controller
also supports up to 15 external SCSI devices through a 68-pin connector on the
computer's back panel. The chassis supports up to three SCSI removable-media
devices.
NOTES: To achieve 80-MB/sec data transfer rates on the primary SCSI channel, you
must use LVD hard-disk drives and either an LVD terminator or a multimode
terminator.
If you install a mix of LVD and non-LVD hard-disk drives, the system can only achieve
40-MB/sec data transfer rates for all SCSI drives. In addition, the LVD drives in this mix
must be capable of reverting to 40 MB/sec. In this configuration, you can terminate
the SCSI subsystem with either a single-ended or multimode terminator.
Dell ships multimode terminators only, regardless of system configuration.
The total length of the SCSI cable for each of the primary and secondary SCSI chan-
nels is 2.5 meters (m).
The total number of SCSI devices connected to the secondary 7880 controller, both
internally and externally, cannot exceed 15.
Using the Integrated SCSI Controllers 7-1