Populating DIMM Sockets
There are four DIMM sockets on the system board, with two sockets per channel. The sockets are
labeled XMM1, XMM2, XMM3, and XMM4. Sockets XMM1 and XMM3 operate in memory channel A.
Sockets XMM2 and XMM4 operate in memory channel B.
Figure 6-15
DIMM Socket Locations
Table 6-1
DIMM Socket Locations
Item
Description
Socket Color
1
XMM2 socket, Channel B (populate third)
White
2
XMM1 socket, Channel A (populate first)
Black
3
XMM4 socket, Channel B (populate fourth)
White
4
XMM3 socket, Channel B (populate second)
Black
NOTE:
DIMM1 must be populated before DIMM2.
DIMM3 must be populated before DIMM4.
The system will automatically operate in single channel mode, dual channel mode, or flex mode,
depending on how the DIMMs are installed.
●
The system will operate in single channel mode if the DIMM sockets are populated in one
channel only.
●
The system will operate in a higher-performing dual channel mode if the total memory capacity
of the DIMMs in Channel A is equal to the total memory capacity of the DIMMs in Channel B.
The technology and device width can vary between the channels. For example, if Channel A is
populated with two 1-GB DIMMs and Channel B is populated with one 2-GB DIMM, the system
will operate in dual channel mode.
●
The system will operate in flex mode if the total memory capacity of the DIMMs in Channel A is
not equal to the total memory capacity of the DIMMs in Channel B. In flex 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. For optimal speed, the channels
Installing Additional Memory
49
