NonStop S-Series Server Description Manual (G06.27+)

Introduction

HP NonStop S-Series Server Description Manual—520331-004

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 could support a theoretical maximum of nine I/O enclosures.

However, this theoretical maximum would be 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 to a maximum of five

directly connected I/O enclosures. That limitation occurs because several ports are

needed to interconnect the processor enclosures.

In a maximum server configuration, as illustrated in Figure 1-2, the four processor

enclosures (unshaded) in the middle of the diagram forms the core tetrahedron.

(Tetrahedron is a method of processor interconnection that is discussed under

Tetrahedral Topology on page 1-26.)

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.