Compaq AlphaServer GS160, Installation Manual

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Overview 1-1
Chapter 1
Overview
The AlphaServer GS160 and GS320 systems are high-performance server
platforms designed for enterprise-level applications. They are distinguished by
a high degree of versatility, scalability, and expandability.
These powerful, switch-based systems use four Alpha microprocessors per quad
building block (QBB). Two QBBs paired back-to-back and rotated 180º with
reference to each other form a system box, which is the smallest system-level
configurable component of the
AlphaServer GS320.
1.1 The System
The system consists of a power cabinet and one system cabinet or two system
cabinets, depending on the configuration. The power cabinet contains the power
supplies, the I/O components—the PCI boxes and storage units—and the OCP
(operator control panel). The system cabinets house the system boxes that carry
interconnect modules as well as CPU and memory modules.
The system cabinet can be configured with one or two system boxes. The first
system box is located in the lower cavity of the cabinet and the second system
box is inserted in the upper cavity. A fully configured system consists of a
power cabinet and two system cabinets—system cabinet 1 and system cabinet
2—each system cabinet containing two system boxes.
Each QBB backplane contains a switch that acts as an interconnect between the
CPU modules, memory modules, I/O riser modules, and the global port module.
In an 8-processor configuration (single system box) a distribution board
interfaces the two QBBs directly through their global ports. In configurations
with more than one system box, a hierarchical switch replaces the distribution
card
and adds a second level switch to route information between the system
boxes.