HP ProLiant DL980 G7, Руководство по техническому обслуживанию и ремонту

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Memory performance optimization
The server supports 128 DIMMS across eight Multi-core processors (64 DIMMs across four multi-core
processors, in each processor memory drawer). While there are many DIMM population
configurations that can support any total memory size, optimal performance is achieved when
populated DIMMs can take advantage of the Intel® Xeon™ 7500-series processor architecture.
To achieve the best performance for a given memory processor configuration, observe the following
guidelines:
•
The largest contributor to maximum memory bandwidth performance is to use both memory
controllers inside the processor. To achieve maximum memory bandwidth performance,
populate both memory cartridges for each installed processor. This configuration is required
for this server.
•
The second largest contributor to performance is to populate each DDR3 channel in each
memory cartridge. To achieve this, the minimum DIMM count per cartridge is four DIMMs
installed in DIMM pair locations A and B.
•
The next largest contributor to performance is the number of ranks per DIMM. Dual-rank DIMMs
perform significantly better than single-rank DIMMs. Quad-rank DIMMs offer a further
performance boost.
•
The best performance is obtained when all installed processors are enabled for Hemisphere
mode. Hemisphere mode is optimum when four or eight DIMMs are installed per cartridge.
Hemisphere mode can be achieved with two or six DIMMs per cartridge (2 cartridges per
processor), but this configuration is not optimal for Hemisphere mode. Hemisphere mode is
required for this server.
•
Maximum throughput is achieved when all memory cartridges are fully populated with the
maximum number of eight quad-rank DIMMs per cartridge.
Plan the memory configurations using identical DIMMs to achieve the memory size target, taking
into account that 64- and 128-DIMM count configurations result in the highest performance. Using
a four-processor configuration as an example, do the following:
•
If the initial memory target is 64 GB, populate a four-processor system with eight cartridges
of four 2-GB DIMMs each for a total of 32 DIMMs.
•
For 4-GB DIMMs, the initial memory target is 128-GB using 32 DIMMs. The maximum
expansion target is 256 GB with 64 DIMMs.
•
For 8-GB DIMMs, the initial memory target is 256-GB using 32 DIMMs. The maximum
expansion target is 512 GB with 64 DIMMs.
•
The maximum system memory capability is achieved with an initial memory target of 1024
GB with 32 x 32-GB DIMMs and 2 TB with 64 x 32-GB DIMMs.
For an eight-processor configuration, the same example applies, but must be done for both processor
memory drawers, resulting a doubling of the memory capacity, and a 4 TB maximum with 128 x
32 GB DIMMs.
Memory RAS
The server supports the following AMP modes:
•
Advanced ECC memory mode provides the greatest memory capacity for a given DIMM size
and provides x4 and x8 SDDC. This mode is the default option for this server. For more
information, see "Advanced ECC memory population guidelines (
“Advanced ECC memory
population guidelines” (page 39) )."
•
Online Spare memory mode provides protection against persistent DRAM failure. Rank-sparing
is more efficient than DIMM-sparing since only a portion of a DIMM is set aside for memory
38 Removal and replacement procedures