Supported Memory - Dell External OEMR XL R720XD Technical Manual

Table 8 lists the DIMMs supported on the R720 and R720xd. For the latest information on supported
memory, visit Dell.com.
Only
Capacity
(GB)
2
2
2
4
4
4
4
8
8
16
16
32
32
Flexible memory configurations are supported on the R720 and R720xd, ranging from capacities of
2 GB (minimum) to 768 GB (maximum). The R720 and R720xd support up to 12 DIMMs per
processor (up to 24 DIMMs in a dual-processor configuration). Each server has four memory
channels per processor, with each channel supporting up to three DIMMs.
Both systems support a flexible memory configuration, according to the following basic rules:

Speed: If DIMMs of different speeds are mixed, all channels across all processors operate at the
slowest DIMM's common frequency.

DIMM type: Only one type of DIMM is allowed per system: UDIMM, RDIMM, or LRDIMM. These
types cannot be mixed.
The following additional memory-population guidelines apply to the R720 and R720xd:

Up to two quad-rank (QR) DIMMs and up to three dual-rank (DR) or single-rank (SR) DIMMs may
be populated per channel.

DIMMs must be installed in each channel, starting with the DIMM farthest from the processor.

DIMMs should be installed with largest rank count to smallest. For example, if DR DIMMS are
mixed with SR DIMMs, DR DIMMS should be placed in the lowest DIMM slots, followed by the SR
DIMMs.
For more information on memory configuration and population, see the
R720xd Systems Owner's Manual
PowerEdge R720 and R720xd Technical Guide
22
Speed Ranks per
Type
(MT/s) DIMM
1333 RDIMM 1
1333 UDIMM 1
1600 RDIMM 1
1333 RDIMM 2
1333 RDIMM 1
1333 UDIMM 2
1600 RDIMM 2
1333 RDIMM 2
1600 RDIMM 2
1333 RDIMM 2
1600 RDIMM 2
1333 LRDIMM 4
1333 RDIMM 4
on Support.Dell.com/Manuals.
Data
SDDC support
width
x8 Advanced ECC
x8 Advanced ECC
x8 Advanced ECC
x8 Advanced ECC
x4 All modes
x8 Advanced ECC
x8 Advanced ECC
x4 All modes
x4 All modes
x4 All modes
x4 All modes
x4 All modes
x4 All modes
Dell PowerEdge R720 and
Voltage
1.35
1.35
1.5
1.35
1.35
1.35
1.5
1.35
1.5
1.35
1.5
1.35
1.35