General memory module installation guidelines, Non-optimal memory configurations, Memory sparing support – Dell PowerVault DP600 User Manual
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Installing System Components
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General Memory Module Installation Guidelines
To ensure optimal performance of your system, observe the following
guidelines when configuring your system memory.
•
Use only qualified FBDs. FBDs can be either single-ranked or dual-
ranked. FBDs marked with a 1R are single-ranked and modules marked
with a 2R are dual-ranked.
•
A minimum of two identical FBDs must installed.
•
DIMM sockets must be populated by lowest number first.
•
FBDs must be installed in pairs of matched memory size, speed, and
technology, and the total number of FBDs in the configuration must total
two, four, eight, or twelve. For best system performance, all four, eight, or
twelve FBDs should be identical memory size, speed, and technology.
•
Memory sparing and memory mirroring require eight or twelve FBDs,
and all FBDs must be of identical memory size, speed, and technology.
•
Memory sparing and memory mirroring cannot be implemented at the
same time.
Non-Optimal Memory Configurations
System performance can be affected if your memory configuration does not
conform to the preceding installation guidelines. Your system may issue an
error message during startup stating that your memory configuration is
non-optimal.
Memory Sparing Support
The system supports memory sparing if eight or twelve identical memory
modules are installed in the system. The memory sparing feature must be
enabled in the System Setup program and can be used only if memory
mirroring is not enabled.
Memory sparing allocates four ranks of DIMM memory to the spare bank of
memory sparing. These four ranks consist of the first rank of memory in
DIMM sockets 1 through 4. For single-rank DIMMs, the entire capacity of
the four DIMMs is allocated to sparing whereas for dual-rank DIMMs, only
half of the four-DIMM capacity is allocated to sparing. Table 3-1 shows how
memory sparing splits the available and spared memory in each of the single-
and dual-ranked memory module combinations.
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