Dell PowerEdge M620 Техническое руководство - Страница 20

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Dell PowerEdge M620 Техническое руководство

Flexible memory configuration

The M620 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: UDIMM, RDIMM or LRDIMM. These

types cannot be mixed.

The following additional memory population guidelines apply to the M620:



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

Memory speed

The M620 supports memory speeds of 1866MT/s, 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.

DIMM

type

UDIMM

RDIMM

PowerEdge M620 Technical Guide

on Dell.com/Support/Manuals.

Table 8.

Memory speed capabilities

Number

DIMM

of DIMMs

800*

1066*

∞

Dell PowerEdge M620

Speed (MT/s)

1333

1600

∞

1866

∞