Owners Manual

Installing System Components 131
The maximum memory that is supported on your system varies according to
the types and sizes of memory modules being used:
• Single-rank and dual-rank RDIMMs of sizes 2-GB, 4-GB, and 8-GB
(when available) are supported for a total of up to 144 GB.
• Quad-rank RDIMMs (two per channel) are supported for a total of up to
96 GB.
• 1-GB and 2-GB UDIMMs are supported for a total of up to 24 GB.
General Memory Module Installation Guidelines
To ensure optimal performance of your system, observe the following general
guidelines when configuring your system memory.
NOTE: Memory configurations that fail to observe these guidelines can cause your
system to halt at startup without any video output of system messages.
• RDIMMs and UDIMMs cannot be mixed.
• No more than two UDIMMs can be populated per channel.
• Except for memory channels that are unused, all populated memory
channels must have identical configurations.
• Memory modules of different sizes can be mixed within a memory channel
(for example, 2-GB, 8-GB, and 4-GB), but all populated channels must
have identical configurations.
• For Optimizer Mode, memory modules are installed in the numeric order
of the sockets beginning with A1 or B1.
• For Memory Mirroring or Advanced ECC Mode, the three sockets furthest
from the processor are unused and memory modules are installed
beginning with socket A2 or B2 and proceeding in the numeric order of the
remaining sockets (for example, A2, A3, A5, A6, A8, and A9).
• Advanced ECC Mode requires x4 or x8 DRAM device widths.
• The memory speed of each channel depends on the memory
configuration:
– For single or dual-rank memory modules:
• One memory module per channel supports up to 1333 MHz.
• Two memory modules per channel supports up to 1067 MHz.