Service manual

1-84 AlphaServer GS80/160/320 Service Manual
1.21.3 PCI Box Configuration
Each QBB can have two I/O risers supporting up to two PCI boxes. A
cable connects a local I/O riser (in the QBB) to a remote I/O riser (in the
PCI box). Each PCI box can have up to two remote I/O risers creating
two three-slot and two four-slot 64-bit PCI buses. Cable connectors for
the two remote I/O risers are shown as Riser 0 and Riser 1 in Figure 1–
38. PCI slots and logical hoses are listed in Table 1– 12.
Figure 1– 38 PCI Slot Locations
PK-0643-99
6754 321
1
5647132Slot
Riser Riser 0
PCI Slot Configuration Guidelines
• I/O riser 0 must be installed.
• The standard I/O module is always installed in riser 0-slot 1.
• Install high-powered modules in slots with one inch module pitch (all slots
except riser 0-slot 5, riser 0-slot 6, riser 1-slot 5, and riser 1-slot 6).
• Install high-performance adapters across multiple bus/hose segments to get
maximum performance.
• VGA graphics options must be installed in riser 0-slot 2 or riser 0-slot 3.