Installation guide

Chapter 1
HP Integrity rx7640 Server and HP 9000 rp7440 Server Overview
Detailed Server Description
32
The memory subsystem comprises four independent quadrants. Each quadrant has its own memory data bus
connected from the cell controller to the two buffers for the memory quadrant. Each quadrant also has two
memory control buses; one for each buffer.
Figure 1-9 Memory Subsystem
DIMMs
The memory DIMMs used by the server are custom designed by HP. Each DIMM contains DDR-II SDRAM
memory that operates at 533 MT/s. Industry standard DIMM modules do not support the high availability
and shared memory features of the server. Therefore, industry standard DIMM modules are not supported.
The server supports DIMMs with densities of 1, 2, and 4 Gb. Table 1-2 on page 33 lists each supported DIMM
size, the resulting total system capacity, and the memory component density. Each DIMM is connected to two
buffer chips on the cell board.
See Appendix C for more information on DIMM slot mapping and valid memory configurations.