Memory Configurations - Dell PowerEdge M620 Technical Manual

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
The M620 supports memory speeds of 1600MT/s, 1333MT/s, 1066MT/s, and 800MT/s 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 M620, based on the
population of the number and type of DIMMs per memory channel.
on Support.Dell.com/Manuals.
Dell PowerEdge M620