Specifications
19 PowerEdge M420 Technical Guide
Capacity
(GB)
Speed
(MT/s)
Type
Ranks
per
DIMM
Data
width
SDDC support
Voltage
2
1333
RDIMM
1
x8
Advanced ECC
1.35
4
1333
RDIMM
2
x8
Advanced ECC
1.35
4
1600
RDIMM
2
x8
Advanced ECC
1.5
4
1333
RDIMM
1
x4
All modes
1.35
8
1333
RDIMM
2
x4
All modes
1.35
8
1600
RDIMM
2
x4
All modes
1.5
16
1600
RDIMM
2
x4
All modes
1.5
16
1333
RDIMM
2
x4
All modes
1.35
32
1
1333
RDIMM
4
x4
All modes
1.35
1
Available Q3 2012
Flexible memory configurations are supported on the M420, ranging from capacities of 2 GB to
192 GB. The M420 supports up to 3 DIMMs per processor (up to 6 DIMMs in a dual-processor
configuration). Each processor has three memory channels, with each channel supporting a single
DIMM.
The M420 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.
The following additional memory-population guidelines also apply to the M420:
A single quad-rank (QR) DIMM, dual-rank (DR), or single-rank (SR) DIMM may be populated on
each channel.
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
Dell PowerEdge M420
Systems Owner’s Manual
on Support.Dell.com/Manuals.
Memory speeds of 1600 MT/s and 1333 MT/s are supported on the M420, depending on the DIMM
types installed and the configuration. All memory on all processors and channels run at the same
speed and voltage. By default, the system runs at the highest speed for the channel with the lowest
DIMM voltage and speed. The operating speed of the memory is also determined by the maximum
speed supported by the processor, the speed settings in the BIOS, and the operating voltage of the
system.
Table 8 lists the memory configuration and performance details for the M420, based on the
population of the number and type of DIMMs per memory channel.