HP Integrity Superdome SX1000 User Guide, Sixth Edition - HP Integrity Superdo - Page 22

Overview Cell Board Cell Board The cell board with its firmware is the biggest change to the Superdome family. It provides the processing and memory resources required by each hp Integrity Superdome system configuration. Each cell board uses up to four Itanium® 2 processor modules hp Integrity Superdome) or up to four PA-8800, dual-core, PA-RISC processor modules (hp 9000 Superdome), a single cell (or coherency) controller (CC), a high-speed crossbar interface, a high-speed I/O interface, eight memory controller CCs, capacity for up to 32 high-density DIMMs, high-speed clock-distribution circuitry, a utility subsystem interface, scan (JTAG) circuitry for manufacturing test, and a low-voltage DC power interface. The system backplane accommodates up to eight cell boards allowing up to 32 processor modules and up to 256 DIMMs in a single system cabinet. The cell power board (OCPB) is separate from the cell board. An OCPB can attach to any cell board. Figure 1-5 New hp Integrity Superdome Cell Board Power Board Attaches to Cell Board Cell Board The heart of the cell board, the coherency controller (CC), provides a Front Side Bus (FSB) interface to each of two processor module pairs. The communication bandwidth (6.4 GB/s at 200 MHz) of both FSB interfaces on the CC is, therefore, split between two processor modules. Interfaces external to the cell board provided by the CC constitute a crossbar interface, referred to as the fabric, and a remote I/O subsystem link. The fabric interface allows multiple cell boards to communicate with each other across a self-correcting, high-speed (8 GB/s) communication pathway. The remote I/O link provides a self-correcting, high-speed (2 GB/s) communication pathway between the cell board and the I/O subsystem through a pair of cables. In addition, the CC also provides the cell board with its own interface to the cell board's local memory subsystem. 10 Chapter 1