M
EMORY
P
OPULATION
R
ULES
I
NSTALLING
H
ARDWARE
2-17
Memory Population Rules
When considering the memory configuration of your server, you should consider the fol-
lowing items:
DIMMs within the server should all be the same size, speed, and type. It is not recom-
mended to mix different sized or different speed DIMMs in the same system. Mixing
DIMM modules results in the system setting the memory speed to that of the slow-
est installed DIMMs.
There are white and black DIMM slots. Populate the white slots in a bank first.
DIMMs can be used either in a one DIMM per Channel (1DPC) configuration or in a
two DIMMs per Channel (2DPC) configuration.
Low-voltage (1.35 V) DIMM and standard-voltage DIMM (1.5 V) can be mixed in the
system. However, the system BIOS defaults to standard-voltage operation.
The following denotes the memory support matrix.
Table 1: Memory Support Matrix
2 SPC
1 DPC
2 DPC
1.5V
SR/DR
1600
1600
QR
1066
800
LRDIMM
1333
1333
1.35V
SR/DR
1600(*)
1333
QR
1066(*)
800
LRDIMM
1333(*)
1333(*)
Table 2: Memory Population Configuration
DIMM_A1
DIMM_A2
DIMM_B1
DIMM_B2
Mirror
Spare
Lockstep
Configuration 1
x
Configuration 2
x
Configuration 3
x
x
o
Configuration 4
x
x
o
Configuration 5
x
x
o
o
Configuration 6
x
x
x
Configuration 7
x
x
x
Configuration 8
x
x
x
x
o
o
o
x: Indicates the DIMM population location.
o: Indicates the supported function.
