Memory Sparing Support
Memory sparing is supported in systems that have one of the fully populated memory configurations shown in Table3-1. The memory sparing feature must be
enabled in the Memory Information screen of the System Setup program. See Using the System Setup Program.
Memory sparing is applied independently to the two groups of DIMMs on opposite sides of the processor sockets. To support memory sparing, all DIMM
sockets within a DIMM group must be populated.
When enabled, memory sparing allocates and reserves ranks of memory from the installed DIMMs to act as spare memory in the event of a memory channel
failure. A memory channel uses paired DIMMs; for memory sparing to work, DIMMs must be paired as spares also.
Memory sparing allocates only the first rank of memory of a DIMM. For a single-rank DIMM, the entire capacity of the DIMM must be allocated for sparing along
with the adjacent single-rank DIMM to spare a memory channel. For dual-rank DIMMs, two DIMMs are also required for sparing, but as only the first rank of
each DIMM is allocated, only half of a dual-rank DIMM's capacity is allocated for sparing. The second ranks on both DIMMs are available memory.
Memory sparing calculates the appropriate DIMMs to spare by searching the DIMM sockets, starting with the higher-numbered socket pair (specifically, sockets
3 and 4 or sockets 7 and 8), for an amount of memory large enough to spare one of the available channels of memory. If the DIMMs in these sockets are
sufficient to spare a channel of the available memory, the first rank of each of those two DIMMs are spared. If the amount of memory is not large enough to
spare an available memory channel, the system spares the DIMM ranks in the lower-numbered sockets. Table3-2 shows how memory sparing works in
various memory configurations.

Table 3-2. Memory Sparing Configurations

Installing Memory Modules
1. Turn off the system, including any attached peripherals, and disconnect the system from the electrical outlet.
2. Open the system. See Opening the System.
3. Remove the memory cooling shroud. See Removing the Memory Module Cooling Shrouds.
8 GB
2 GB
12 GB
2 GB
1 GB
16 GB
2 GB
2 GB
24 GB
2 GB
2 GB
1 GB
32 GB
2 GB
2 GB
2 GB
16 GB
4 GB
24 GB
4 GB
2 GB
32 GB
4 GB
4 GB
48 GB
4 GB
4 GB
2 GB
64 GB
4 GB
4 GB
4 GB
32 GB
8 GB
48 GB
8 GB
4 GB
64 GB
8 GB
8 GB
96 GB
8 GB
8 GB
4 GB
128 GB
8 GB
8 GB
8 GB
NOTE: The Memory sparing and node interleaving features cannot be used at the same time. To use memory sparing, you must disable the Node
Interleaving option in the System Setup program.
DIMMs
Available Memory
A1, A2, B1, B2
A3, A4, B3, B4
A5, A6, B5, B6
A7, A8, B7, B8
512 MB
512 MB
512 MB
512 MB
6 GB
1 GB
1 GB
1 GB
1 GB
12 GB
2 GB
2 GB
2 GB
2 GB
28 GB
4 GB
4 GB
4 GB
4 GB
56 GB
8 GB
8 GB
8 GB
8 GB
112 GB
Indicates a spared single-rank DIMM (512-MB or 1-GB). The entire capacity of this DIMM is reserved for sparing.
Indicates a spared dual-rank DIMM (2-GB and higher). One-half of this DIMM's capacity is reserved for sparing.
CAUTION: Many repairs may only be done by a certified service technician. You should only perform troubleshooting and simple repairs as
authorized in your product documentation, or as directed by the online or telephone service and support team. Damage due to servicing that is not
authorized by Dell is not covered by your warranty. Read and follow the safety instructions that came with the product.