Dell EMC PowerEdge R540 - Page 103

Memory Operating Mode Description
running even during a catastrophic memory failure by switching
over to the mirrored copy. The installation guidelines to enable
Mirror Mode require that the memory modules be identical in size,
speed, and technology, and they must be populated in sets of 6 per
processor.
Single Rank Spare Mode Single Rank Spare Mode allocates one rank per channel as a spare.
If excessive correctable errors occur in a rank or channel, while the
operating system is running, they are moved to the spare area to
prevent errors from causing an uncorrectable failure. Requires two
or more ranks to be populated in each channel.
Multi Rank Spare Mode Multi Rank Spare Mode allocates two ranks per channel as a spare.
If excessive correctable errors occur in a rank or channel, while the
operating system is running, they are moved to the spare area to
prevent errors from causing an uncorrectable failure. Requires three
or more ranks to be populated in each 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 sixteen 16 GB
dual-rank memory modules, the available system memory: 16 GB x
16(memory modules) - 8GB(1 rank sparing/channel) x 12(channel) =
256 GB - 96 GB = 160 GB
For multi rank sparing, in a dual-processor conguration with
sixteen 64 GB quad-rank memory modules, the available system
memory: 64 GB x 16(memory modules) - 32 GB(2 rank sparing/
channel) x 12 (channel) = 1024 GB - 384 GB = 640 GB
NOTE: To use memory sparing, this feature must be
enabled in the BIOS menu of System Setup.
NOTE: Memory sparing does not oer protection against a
multi-bit uncorrectable error.
Dell Fault Resilient Mode The Dell Fault Resilient Mode if enabled, the BIOS creates an area
of memory that is fault resilient. This mode can be used by an OS
that supports the feature to load critical applications or enables the
OS kernel to maximize system availability.
Optimizer 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.
• Dual processor: Populate the slots in round robin sequence starting with processor 1.
NOTE
: Processor 1 and processor 2 population should match.
Table 45. Memory population rules
Processor Conguration Memory population Memory population information
Single processor Optimizer (Independent channel)
population order
1, 2, 3, 4, 5, 6, 7, 8, 9, 10
• Populate in this order, odd amount
allowed.
Installing and removing system components 103