HP 9000 rp8440 Site Preparation Guide, Fourth Edition - HP Integrity rx8640, H - Page 19

Central Processor Units The cell board can hold up to four CPU modules. Each CPU module can contain up to two CPU cores on a single die. Modules are populated in increments of one. On a cell board, the processor modules must be the same family, type, and clock frequencies. Mixing of different processors on a cell or a partition is not supported. See Table 1-1 for the load order that must be maintained when adding processor modules to the cell board. See Figure 1-7 for the locations on the cell board for installing processor modules. NOTE: Unlike previous HP cell based systems, the server cell board does not require that a termination module be installed at the end of an unused FSB. System firmware is allowed to disable an unused FSB in the CC. This enables both sockets of the unused bus to remain unpopulated. Table 1-1 Cell Board CPU Module Load Order Number of CPU Modules Installed Socket 2 1 Empty slot 2 CPU installed 3 CPU installed 4 CPU installed Socket 3 Empty slot Empty slot Empty slot CPU installed Socket 1 Empty slot Empty slot CPU installed CPU installed Socket 0 CPU installed CPU installed CPU installed CPU installed Figure 1-7 Socket Locations on Cell Board Socket 2 Socket 3 Socket 1 Socket 0 Cell Controller Memory Subsystem Figure 1-8 shows a simplified view of the memory subsystem. It consists of four independent access paths, each path having its own address bus, control bus, data bus, and DIMMs . Address and control signals are fanned out through register ports to the synchronous dynamic random access memory (SDRAM) on the DIMMs. Detailed Server Description 19