150 Installing System Components
System Memory
Each system board has 16 memory module sockets for the installation of
DDR3 unbuffered ECC DIMMs (ECC UDIMMs), registered DIMMs
(RDIMMs), and load reduced DIMMs (LRDIMMs) to support processor 1
and processor 2. See "System Board Connectors" on page219 for the location
of the memory modules.

Memory Module Installation Guidelines

Follow these guidelines when installing memory modules on the sled system
board.
• Use only Dell approved R/LR/UDIMM DDR3 memory modules in 2 GB,
4 GB, 8 GB, 16 GB, and 32 GB capacities. DIMM types (R/LR/UDIMM)
cannot be mixed.
• DIMM slots are numbered 1 to 8 and designated by two channels. The
number of channels used and the allowable configuration depend on the
memory mode selected in the System Setup program.
• DIMMs must be installed in each channel st arting with the DIMM socket
farthest from the processor, per Table3-1.
• Memory optimized mode is supported on the sled system board.
• Memory sparing and memory mirroring are supported on the sled system
board. Memory sparing requires that all the DIMMs are identically
populated in all 4 channels. One channel will be the spare and not
accessible as system memory until brought online to replace a failing
channel. For memory mirroring, two channels operate as mirrors for each
other, identical DIMMs must be installed in the same slots across both
channels.