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

Introduction

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

1-4

Maximum Server Configuration

Up to 16 processors can be supported in a single server. With two processors

contained in a processor enclosure, a 16-processor system would have eight

processor enclosures. Processor enclosures are shown unshaded in Figure 1-2. The

shaded boxes represent I/O enclosures.

One processor enclosure can support a theoretical maximum of nine I/O enclosures.

However, this theoretical maximum is possible only for a single, stand-alone processor

enclosure.

When multiple processor enclosures are interconnected, the number of I/O enclosures

that can be supported is reduced. In a maximum configuration, as illustrated in

Figure 1-2, each of the four of the processor enclosures forming the core tetrahedron

is limited to a maximum of five directly connected I/O enclosures. (Tetrahedron is a

method of processor interconnection that is discussed under Tetrahedral Topology on

page 1-26.) In Figure 1-2, the four processor enclosures (unshaded) in the middle of

the diagram are the core tetrahedron.

The outer groupings of enclosures (top and bottom of the figure) also contain

processor enclosures. Each of those processor enclosures is connected to the nearest

processor enclosure in the core tetrahedron, thus doubling the number of processors

that are supported in this maximum configuration. Each of those outer processor

enclosures, in turn, can have four I/O enclosures associated with it.

With all possible processor and I/O enclosures present, as in Figure 1-2, the maximum

possible server arrangement is 8 processor enclosures and 36 I/O enclosures.