Compaq GS160 - Manual (Page 17)

Introduction 1-5
1.3 System Architecture
Each QBB in a GS160/320 system and each QBB (system drawer) in a
GS80 system has a backplane and a switch supporting the CPU
modules, memory modules, and I/O riser modules.
Figure 1–2 shows
two QBBs in a single-box system.
Figure 1–2 Sample System Architecture
System Box
CPU
MEM
I/O GP
CPU CPU CPU
Switch
MEM MEM MEM
Distribution
Board
To PCI Boxes
To PCI Boxes
CPU
MEM
I/O GP
CPU CPU CPU
Switch
MEM MEM MEM
PK-0601A-98
The backplane of each QBB (GS160/320 systems) and drawer (GS80 rack
systems) contains the switch that interconnects the CPU modules, memory
modules, and I/O riser modules.
The global port and distribution board provide the interconnect for the QBBs.
In a two-box system, a hierarchical switch is used as the interconnect, in place
of the distribution board.
I/O riser modules connect the PCI boxes to the QBB backplane.