Dell PowerEdge M820 Technical Manual page 18

Table 7 lists the DIMMs that are supported on the M820. For the latest information on supported
memory, visit Dell.com.
Only
Capacity
(GB)
2
2
2
4
4
4
4
8
8
8
16
16
16
32
32
Flexible memory configurations are supported on the M820, ranging from capacities of 2GB to
1.5TB. The M820 supports up to 12 DIMMs per processor (up to 48 DIMMs in a four-processor
configuration). Each processor has 4 memory channels, with each channel supporting up to 3
DIMMs.
The M820 supports 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: RDIMM or LRDIMM. These types

cannot be mixed.
The following additional memory population guidelines apply to the M820:
Up to two quad-rank (QR) DIMMs and up to three dual-rank (DR) or single-rank (SR) DIMMs may

be populated per channel. Although an LRDIMM is physically a QR DIMM, logic on the LRDIMM
can make it appear as a DR DIMM to the system, allowing up to three LDRIMMs 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
Systems Owner's Manual
PowerEdge M820 Technical Guide
18
Speed
Type
(MT/s)
1600 RDIMM
1333 RDIMM
1333 RDIMM
1333 RDIMM
1600 RDIMM
1333 RDIMM
1333 RDIMM
1333 RDIMM
1333 RDIMM
1600 RDIMM
1066 RDIMM
1600 RDIMM
1333 RDIMM
1333 LRDIMM
1333 RDIMM
on Support.Dell.com/Manuals.
Ranks
Data
per SDDC support
width
DIMM
1 x8 Advanced ECC
1 x8 Advanced ECC
1 x8 Advanced ECC
2 x8 Advanced ECC
2 x8 Advanced ECC
1 x4 All modes
2 x8 Advanced ECC
2 x4 All modes
2 x4 All modes
2 x4 All modes
4 x4 All modes
2 x4 All modes
2 x4 All modes
4 x4 All modes
4 x4 All modes
Voltage
1.5
1.35
1.35
1.35
1.5
1.35
1.35
1.35
1.35
1.5
1.35
1.5
1.35
1.35
1.35
Dell PowerEdge M820