Adaptec 131U2 - AAA RAID Controller, Installation And Hardware Manual, Page: 23 / 82

2-9
Installing the Hardware
Connecting SCSI Devices
The AAA-131U2/133U2 supports both internal and external SCSI
devices. Each channel supports up to 15 SCSI devices—Ultra2 SCSI
devices alone or a combination of Ultra2 and Ultra SCSI devices.
Using Adaptec SpeedFlex
™
technology, the 50-pin narrow connector
on Channel A supports up to seven Fast/Narrow SCSI devices
without affecting the performance of Ultra2 devices connected to
Channel A internal and external Ultra2 connectors. Before connect-
ing devices to the AAA-131U2/133U2, be sure to also review Setting
Up SCSI Devices on page 2-6.
Note:
We recommend keeping Ultra2 devices on separate
channels from non-Ultra2 devices. Peak transfer rates on
Ultra2 channels are 80 MBytes/sec. Connecting a non-
Ultra2 device to an Ultra2 SCSI channel limits the entire
channel to lower performance levels (up to 40 MBytes/sec).
If you have internal SCSI devices, mount each device in an available
drive bay inside your computer, as shown in Figure 2-6. Refer to
your computer and device documentation for instructions on install-
ing devices inside your computer.
Note:
If you are installing your SCSI devices inside an
external array enclosure, see External SCSI Array Enclosures
(Storage Subsystems) on page 2-18.
Figure 2-6. Internal SCSI Device Mounted in Drive Bay Inside Your Computer
Internal SCSI Device