Mode-Specific Guidelines - Dell EMC PowerEdge T440 Installation And Service Manual

DIMM population update for Performance Optimized mode with quantity of 4 and 8 DIMMs per processor.
• When the DIMM quantity is 4 per processor, the population is slot 1, 2, 4, 5.
• When the DIMM quantity is 8 per processor, the population is slot 1, 2, 4, 5, 7, 8, 9, 10.

Mode-specific guidelines

The configurations allowed depend on the memory mode selected in the System BIOS.
Table 38. Memory operating modes
Memory Operating Mode
Optimizer Mode
Mirror Mode
Single Rank Spare Mode
Multi Rank Spare Mode
104 Installing and removing system components
Description
The Optimizer Mode if enabled, the DRAM controllers operate
independently in the 64-bit mode and provide optimized memory
performance.
The Mirror Mode if enabled, the system maintains two identical
copies of data in memory, and the total available system memory is
one half of the total installed physical memory. Half of the installed
memory is used to mirror the active memory modules. This feature
provides maximum reliability and enables the system to continue
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 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 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 configuration 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 configuration 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 offer protection against a
multi-bit uncorrectable error.