Memory Speeds and PopulationThe 12th generation of PowerEdge™ servers offers a high level of performance in their memory subsystems with offerings that include up to 1866MT/s speed. Critical design and testing elements ensure that Dell server memory achieve the desired speeds.The loading within a channel significantly affects memory speed. The following tables illustrate the maximum achievable speed based on memory loads:
Green boxes are defaults for performance/per watt
White boxes (with lower voltage) can be chosen to save power but run slower
White boxes (with higher voltage) can be chosen through custom configuration in the bios
DIMM Type
DIMM Ranking
DIMM Rated Voltage, Speed
12thGeneration Memory (EP, 3DPC Platforms) *DPC means DIMMs per channel.
1 DPC
2 DPC
3 DPC
1.35V
1.5V
1.35V
1.5V
1.35V
1.5V
RDIMM
1R/DR
DDR3 (1.5V),
1866
1866
1866
1333
RDIMM
1R/DR
DDR3L (1.35V/1.5V),
1600
1600
1600
1600
1600
1066
1333
UDIMM
1R/DR
DDR3L (1.35V/1.5V),
1600
1600
1600
1600
1600
RDIMM
4R
DDR3L (1.35V/1.5V),
1333
1066
1333
1066
1066
LRDIMM
4R
DDR3L (1.5V),
1866
1866
1600
1333*
LRDIMM
4R
DDR3L (1.35V/1.5V),
1600
1600
1600
1600
1600
1066
1333*
*For PowerEdge T620, the speed clocks down to 1066MT/s.
DIMM Type
DIMM Ranking
DIMM Rated Voltage, Speed
12th Generation Memory (EN, 2DPC Platforms)
1 DPC
2 DPC
1.35V
1.5V
1.35V
1.5V
RDIMM
SR/DR
DDR3L (1.5V),
1600
1600
1600
1600
1600
RDIMM
SR/DR
DDR3L (1.35V/1.5V),
1333
1333
1333
1333
1333
UDIMM
SR/DR
DDR3L (1.35V/1.5V),
1600
1600
1600
1600
1600
RDIMM
QR
DDR3L (1.35V/1.5V),
1333
1066
1333
1066
1066
LRDIMM
QR
DDR3L (1.35V/1.5V),
1333
The M420 is a 1DPC platform and has a unique table for speed:
DIMM Type
DIMM Ranking
DIMM Rated Voltage, Speed
12th Generation Memory (EN, 1DPC Platform — M420)
1 DPC
2 DPC
1.35V
1.5V
1.35V
1.5V
RDIMM
SR/DR
DDR3 (1.5V),
1600
1600
1600
RDIMM
SR/DR
DDR3L (1.35V/1.5V),
1333
1333
1333
UDIMM
SR/DR
DDR3L (1.35V/1.5V),
1600
1600
1600
RDIMM
QR
DDR3L (1.35V/1.5V),
1333
1333
1333
LRDIMM
QR
DDR3L (1.35V/1.5V),
1333
DIMM Type
DIMM Ranking
DIMM Rated Voltage, Speed
12th Generation Memory (PEC EP, 2DPC Platforms) *DPC means DIMMs per channel.
1 DPC
2 DPC
1.35V
1.5V
1.35V
1.5V
RDIMM
1R/2R
DDR3 (1.5V),
1866
1866
1600
RDIMM
1R/2R
DDR3L (1.35V/1.5V),
1600
1333
1600
1333
1600
UDIMM
1R/2R
DDR3L (1.35V/1.5V),
1600
1333
1600
1333
1600
RDIMM
4R
DDR3L (1.35V/1.5V),
1333
800
1066
800
800
The Dell 12th generation PowerEdge servers require memory to be populated in a specific order to help ensure correct utilization and optimization of the server. Here are some basic population rules for the Socket R systems:
Dual in-line memory module (DIMMs) should be populated by largest capacity first.
In advanced ECC mode, DIMMs must be populated in matched pairs (same capacity and ranking). Odd numbers of DIMMs are not supported in this mode.
Optimized mode can support even or odd numbers of DIMMs.
For mirroring configurations, each channel must be matched (same capacity and ranking).
Rank sparring requires at least two DIMMs or one quad-ranked DIMM.
Dell EMC | Global Support & Deployment