Dell R420xr owner manual System Memory, Rdimm

System Memory

Your system supports DDR3 unbuffered ECC DIMMs (UDIMM ECC) and registered DIMMs (RDIMMs). It supports DDR3 and DDR3L voltage specifications.

NOTE: MT/s indicates DIMM speed in MegaTransfers per second.

Memory bus operating frequency can be 1600 MT/s, 1333 MT/s, 1066 MT/s, or 800 MT/s depending on:

•DIMM type (UDIMM or RDIMM)

•DIMM configuration (number of ranks)

•maximum frequency of the DIMMs

•number of DIMMs populated per channel

•DIMM operating voltage

•system profile selected (for example, Performance Optimized, Custom, or Dense Configuration Optimized)

•maximum supported DIMM frequency of the processors

The following table shows the memory populations and operating frequencies for the supported configurations.

DIMM	DIMMs	Operating Frequency (in MT/s)		Maximum DIMM Rank/
Type	Populated/			Channel
	Channel
		1.5 V	1.35 V
UDIMM	1	1333, 1066, and 800	1333, 1066 and 800	Dual rank
ECC	2	1333, 1066, and 800	1066 and 800	Dual rank
RDIMM	1	1600, 1333, 1066,	1333, 1066, and 800	Dual rank
		and 800
		1333, 1066, and 800	1066 and 800	Quad rank
	2	1600, 1333, 1066,	1333, 1066, and 800	Dual rank
		and 800
		1066 and 800	1066 and 800	Quad rank

The system contains 12 memory sockets split into two sets of six sockets, one set per processor. Each six-socket set is organized into three channels. In each channel, the release levers of the first socket is marked white and the second black.

NOTE: DIMMs in sockets A1 to A6 are assigned to processor 1 and DIMMs in sockets B1 to B6 are assigned to processor 2.

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