Acer Altos G540 M2 - Manual (Page 86)

3 System upgrade 76
Upgrading the system memory
This section explains the procedures for removing and installing a
fully-buffered memory module.
Memory Configuration Guideline
Altos G540 M2 has twelve DIMM slots. Each CPU controls six DIMM
slots. The DIMM slots support three channel DDR3-1333 registered/
unbuffered ECC memory modules. For CPU1, it will be channel A, B &C.
For CPU2, it will be channel D,E &F. Each channel has 2 sockets. The
farthest socket to CPU is socket 1 (A1,B1,C1,D1,E1,F1 in color BLUE ),
while the nearest one is socket 2 (A2,B2,C2,D2,E2,F2 in color black). For
all memory modes, the socket 1 in each channel should be populated
first. If socket 1 is empty, socket 2 can't be used.
Note:
(1) When you are using a single-processor server, you should
install the memory module into DIMM A1 to DIMM C2
slots.