Populating Dimm Sockets - HP dx2818 - Microtower PC Hardware Reference Manual

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 XMM2 operate in memory channel A.
Sockets XMM3 and XMM4 operate in memory channel B.
Figure 2-6
Table 2-1 DIMM Socket Locations
Item
1
2
3
4
NOTE: A DIMM must occupy the XMM1 socket.
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 512MB DIMMs and Channel B is populated with one 1GB 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
14 Chapter 2 Hardware Upgrades
DIMM Socket Locations
Description
XMM1 socket, Channel A (populate
first)
XMM2 socket, Channel A
XMM3 socket, Channel B (populate
second)
XMM4 socket, Channel B
Socket Color
White
Black
White
Black
ENWW