Owners Manual

Processor Conguration Memory population Memory population information
Single rank sparing
population order
A{1}, B{1},
A{2}, B{2},
A{3}, B{3},
A{4}, B{4},
A{5}, B{5},
A{6}, B{6}
• DIMMs must be populated in the order
specied.
• Requires two ranks or more per channel.
Multi rank sparing
population order
A{1}, B{1},
A{2}, B{2},
A{3}, B{3},
A{4}, B{4},
A{5}, B{5},
A{6}, B{6}
• DIMMs must be populated in the order
specied.
• Requires three ranks or more per channel.
Fault resilient population
order
A{1, 2, 3, 4, 5, 6},
B{1, 2, 3, 4, 5, 6},
A{7, 8, 9, 10, 11, 12},
B{7, 8, 9, 10, 11, 12}
Supported with 6 or 12 DIMMs per processor.
Memory optimized (independent channel) mode
This mode supports Single Device Data Correction (SDDC) only for memory modules that use x4 device width. It does not impose any
specic slot population requirements.
Memory sparing
NOTE
: To use memory sparing, this feature must be enabled in BIOS menu of System Setup.
Table 40. Memory sparing
Type Description
Memory sparing (Single Rank) Memory sparing allocates one rank per channel as a spare. If excessive correctable
errors occur in a rank or channel, they are moved to the spare area while the
operating system is running to prevent errors from causing an uncorrectable failure.
Requires population of two ranks or more per channel.
Memory sparing (Multi Rank) Memory sparing allocates two ranks per channel as a spare. If excessive
correctable errors occur in a rank or channel, they are moved to the spare area
while the operating system is running to prevent errors from causing an
uncorrectable failure. Requires population of three ranks or more per channel.
With single rank memory sparing enabled, the system memory available to the operating system is reduced by one rank per channel. For
example, in a dual-processor conguration with twenty four 16 GB dual-rank memory modules, the available system memory is: 3/4 (ranks/
channel) × 24 (memory modules) × 16 GB = 288 GB, and not 24 (memory modules) × 16 GB = 384 GB. This calculation changes based on
if it is single rank sparing or multi rank sparing. For multi rank sparing, the multiplier changes to 1/2 (ranks/channel).
NOTE
: Memory sparing does not oer protection against a multi-bit uncorrectable error.
76 Installing and removing system components