62 Installing System Components
• The memory speed of each channel depends on the
memory configuration:
– For single- or dual-rank memory modules:
• One memory module per channel supports up to 1333 MHz.
• Two memory modules per channel supports up to 1067 MHz.
– For quad-rank memory modules:
• One memory module per channel supports up to 1067 MHz.
• Two memory modules per channel are limited to 800 MHz,
regardless of memory module speed.
• If quad-rank memory modules are mixed with single- or dual-rank
modules, the quad-rank modules must be installed in the sockets
with the white release levers.
• If memory modules with different speeds are installed, they operate at the
speed of the slowest installed memory module(s).
Mode-Specific Guidelines
Three memory channels are allocated to each processor. The number
ofchannels used and the allowable configurations depend on the
memorymode selected.
Optimizer (Independent Channel) Mode
In this mode, all three channels are populated with identical memory
modules. This mode permits a larger total memory capacity but does not
support SDDC with x8-based memory modules.
A minimal single-channel configuration of one 1 GB memory module per
processor is also supported in this mode.
Table3-1 shows sample memory configurations that follow the appropriate
memory guidelines stated in this section. The samples show identical
memory-module configurations and their the physical and available memory
totals. The tables do not show mixed or quad-rank memory-module
configurations, nor do they address the memory speed considerations
ofany configuration.
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