NonStop S-Series Server Description Manual (G06.24+)

Introduction

HP NonStop S-Series Server Description Manual—520331-003

1-34

Extending the Tetrahedral Topology

As processor enclosures are added, the ultimate plan for the server as a whole is to

grow toward the configuration shown in Figure 1-18.

The first four processor enclosures would be configured as a tetrahedron, like the

middle four enclosures shown in Figure 1-18. Expansion would then occur from any of

the four corners.

The actual sequence of adding processor enclosures can vary.

Each connection from the core tetrahedron to a processor enclosure requires one

router port on a SEB. The addition of I/O enclosures requires additional SEBs, as

described in the next topic, Maximum System With Single Server.)

Because this extension of the configuration makes it possible to grow to 16 processors,

this configuration is called the Tetra 16 topology.

In comparison, the arrangement of including only the core tetrahedron limits the

extension of the configuration to 8 processors, and is therefore called the Tetra 8

topology; see Figure 1-16 on page 1-31.