Hardware Reference Guide

Populating DIMM sockets
There are four DIMM sockets on the system board, with two sockets per channel. The sockets are labeled
DIMM1, DIMM2, DIMM3, and DIMM4. The DIMM1 and DIMM3 sockets operate in memory channel A. The DIMM2
and DIMM4 sockets operate in memory channel B.
For improved performance, install memory modules in the following order: DIMM 4-2-3-1. Note that DIMM 1
is the slot closest to the processor.
The system will automatically operate in single-channel mode, dual-channel mode, or ex mode, depending
on how the DIMMs are installed.
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The system will operate in single-channel mode if the DIMM sockets are populated in one channel only.
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The system will operate in the higher-performing dual-channel mode if the memory capacity of the
DIMM in Channel A is equal to the memory capacity of the DIMM in Channel B.
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The system will operate in ex mode if the memory capacity of the DIMM in Channel A is not equal to the
memory capacity of the DIMM in Channel B. In ex mode, the channel populated with the least amount
of memory describes the total amount of memory assigned to dual channel and the remainder is
assigned to single channel. If one channel will have more memory than the other, the larger amount
should be assigned to channel A.
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In any mode, the maximum operational speed is determined by the slowest DIMM in the system.
Installing system memory 19