HP A9834-9001B - Manual (Page 24)

Chapter 1
Overview
Server Components
24
Server Components
A Superdome system consists of the following types of cabinet assemblies:
At least one Superdome left cabinet. The Superdome cabinets contain all of the processors, memory, and core
devices of the system. They also house most (usually all) of the system's PCI cards. Systems can include both
left and right cabinet assemblies containing a left or right backplane (SD64) respectively.
One or more HP Rack System/E cabinets. These rack cabinets are used to hold the system peripheral devices
such as disk drives.
Optionally, one or more I/O expansion cabinets (Rack System/E). An I/O expansion cabinet is required when a
customer requires more PCI cards than can be accommodated in the Superdome cabinets.
The width of the cabinet assemblies accommodates moving them through standard-sized doorways. The
intake air to the main (cell) card cage is filtered. This filter is removable for cleaning and replacement while
the system is fully operational.
A status display is located on the outside of the front and rear doors of each cabinet. You can therefore
determine basic status of each cabinet without opening any cabinet doors.
The Superdome is a cell-based system. Cells communicate with other via the crossbar on the backplane.
Every cell has its own I/O interface, which can be connected to one 12-slot I/O-card cage via two system bus
adapter (SBA) link cables. Not all SBA links are connected by default due to a physical limitation of four
I/O-card cages per cabinet or node. In addition to these components each node consists of a power subsystem
and a utility subsystem. Three types of Superdome are available: an SD16, an SD32, and an SD64
two-cabinet system (with single-CPU cell board sockets). The SD## represents the maximum number of
available CPU sockets.
An SD16 contains the following components:
- Up to four cell boards
- Four I/O card cages
- Five I/O fans,
- Four system cooling fans,
- Four bulk power supplies (BPS)
- Two Power Distribution Control Assemblies (PDCA)
Two backplane N+1 power supplies provide power for the SD16. The four cell boards are connected to one pair
of crossbar chips (XBC). The backplane of an SD16 is the same as a backplane of an SD32, but the SD16 has
one set of XBCs and the EEPROM is different. On the HUCB utility pcb is a switch that should be set to
TYPE= 1.
An SD32 has up to eight cell boards. All eight cell boards are connected to two pairs of crossbar chips (XBCs).
The SD32 backplane is designed to allow for a system upgrade to an SD64. On an SD32, four of the eight
connectors should use U-Turn cables. The U-Turn cables double the number of links and the bandwidth
between the XBCs and are recommended to achieve best performance.
An SD64 has up to 16 cell boards and requires two cabinets. All 16 cell boards are connected to four pairs of
XBCs. The SD64 consists of a left backplane and a right backplane cabinets which are connected using 12
M-Link cables.