Dell DX6012S - Manual (Page 80)

84
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.
• 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.
• For Memory Mirroring or Advanced ECC Mode, the channel furthest from
the processor is unused and memory modules are installed beginning with
channel A1 or B1 and proceeding with channel A2 or B2.
• Advanced ECC Mode requires memory modules that use 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.
– For quad-rank memory modules:
• One memory module per channel supports up to 1067 MHz.
• Two memory modules per channel are limited to 800 MHz,
regardless of memory module speed.
• 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 operate at the
speed of the slowest installed memory module(s).
book.book Page 84 Friday, February 26, 2010 11:22 AM