Dell PowerEdge R415 - General Memory Module Installation Guidelines

122 Installing System Components
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 prevent
your system from starting and producing any video output.
• RDIMMs and UDIMMs cannot be mixed.
• Except for memory channels that are unused, all populated memory
channels must have identical configurations.
• In a dual-processor configuration, the memory configuration for each
processor must be identical.
• Memory modules of different sizes can be mixed in A1–A4 or B1–B4
(for example, 2 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.
• If quad-rank memory modules are mixed with single- or dual-rank
modules, the quad-rank modules must be installed in the sockets with the
white release levers.
• If memory modules with different speeds are installed, they will operate at
the speed of the slowest installed memory module(s).
Table 3-2, Table 3-3, and Table 3-4 show sample memory configurations that
follow the appropriate memory guidelines stated in this section.
The samples show identical memory-module configurations and the physical
and available memory totals. The tables do not show mixed or quad-rank
memory-module configurations, nor do they address the memory speed
considerations of any configuration.
R415HOM.book Page 122 Friday, September 24, 2010 9:37 AM