System Architecture; Sample System Architecture; System Box - Compaq AlphaServer 160 User Manual

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
To PCI Boxes
To PCI Boxes
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.

System Box

CPU CPU CPU
I/O Switch
MEM MEM MEM
CPU CPU CPU
I/O Switch
MEM MEM MEM
CPU
GP
MEM
Distribution
Board
CPU
GP
MEM
PK-0601A-98
Introduction 1-5