HP d538 - Convertible Minitower Desktop PC Hardware Reference Manual page 25

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.
DIMM Socket Locations
Item Description
DIMM socket XMM1, Channel A
1
DIMM socket XMM2, Channel A
2
DIMM socket XMM3, Channel B
3
DIMM socket XMM4, Channel B
4
Hardware Reference Guide
Socket Color
Black
Blue
Black
Blue
Hardware Upgrades
2-9