HP ProLiant DL580 G7 Server - Manual (Page 43)

Hardware options installation 43
Memory options
This server contains eight memory cartridge connectors in the processor memory drawer. Each memory
cartridge can contain eight DIMMs, for a total of 64 DIMMs.
The server supports the following DIMM speeds:
• Single- and dual-rank PC3-10600 (DDR-1333) DIMMs operating at 1066 MHz
• Quad-rank PC3-8500 (DDR-1066) DIMMs operating at 1066 MHz
Depending on the processor model, the memory clock speed may be reduced to 1066 or 800 MHz.
Memory overview
The HP ProLiant DL580 G7 Server uses the next generation Intel® Xeon® Processor E7-series and
7500-series processor. This processor architecture departs radically from previous Intel Xeon
front-side-bus-based architectures. In front-side bus architectures, the memory controller was incorporated in
the north bridge, which produced a common sharepoint for memory accesses for all processors.
Similar to the dual-socket Intel Xeon 5500 processor, the Intel Xeon Processor E7 and 7500 processor
employs a NUMA architecture incorporating QPI links for point-to-point connectivity between processors and
provides dedicated local memory for each processor. However, instead of directly connecting DIMMs to the
processor, for the sake of higher memory expansion, the Intel Xeon Processor E7 and 7500 processor
includes a memory buffer for each SMI in its memory subsystem.
With this Intel Xeon Processor E7 and 7500 architecture, two memory controllers and four scalable memory
interfaces are embedded in each processor. SMI links run at a higher bit rate. There are four SMIs per
processor, and each SMI link supports two DDR buses through a memory buffer. A four-socket system
provides 6.4 times the memory bandwidth as compared to the previous generation 4S Xeon processors.
DIMM support
The server supports the following DIMMs:
• Single- and dual-rank PC3-10600 (DDR3-1333) DIMMs operating at 1066 MT/s
While single-rank DIMMs are supported, HP recommends dual-rank and quad-rank DIMMs since they
provide significant memory throughput and better memory protection (Online Spare memory mode)
over single-rank DIMMs.
• Quad-rank PC3-8500 (DDR3-1066) DIMMs operating at 1066 MT/s
Single-, dual-, and quad-rank DIMMs
To understand and configure memory protection modes properly, an understanding of single-, dual-, and
quad-rank DIMMs is helpful. Some DIMM configuration requirements are based on these classifications.
A single-rank DIMM has one set of memory chips that is accessed while writing to or reading from the
memory. A dual-rank DIMM is similar to having two single-rank DIMMs on the same module, with only one
rank accessible at a time. A quad-rank DIMM is effectively two dual-rank DIMMs on the same module. Only
one rank is accessible at a time. The server memory control subsystem selects the proper rank within the
DIMM when writing to or reading from the DIMM.