Dell M820 owner manual General Memory Module Installation Guidelines

Processor	DIMM	DIMMs	Operating Frequency (in MT/s)		Maximum DIMM
Type	Type	Populated/			Rank/Channel
		Channel
			1.5 V	1.35 V
			1600,1333, and		Octal rank
			1066
		2	1600,1333, and	1600,1333, and	Quad rank
			1066	1066
			1333 and 1066		Octal rank
		3	1333 and 1066	1066	Quad rank
			1066		Octal Rank

General Memory Module Installation Guidelines

This system supports Flexible Memory Configuration, enabling the system to be configured and run in any valid chipset architectural configuration. The following are the recommended guidelines for best performance:

•RDIMMs and LRDIMMs must not be mixed.

•x4 and x8 DRAM based DIMMs can be mixed. For more information, see Mode-Specific Guidelines.

•Up to two quad-rank RDIMMs and up to three dual- or single-rank RDIMMs can be populated per channel.

•Up to three LRDIMMs can be populated regardless of rank count.

•Populate DIMM sockets only if a processor is installed. For dual-processor systems, sockets A1 to A12 and B1 to B12 are available. For four-processor systems, sockets A1 to A12, B1 to B12, C1 to C12, and D1 to D12 are available.

•Populate the sockets by highest rank count in the following order - first in sockets with white release levers, then black, and then green. For example, to mix quad-rank and dual-rank DIMMs, populate quad-rank DIMMs in the sockets with white release tabs and dual-rank DIMMs in the sockets with black release tabs.

•In a dual- or four-processor configuration, the memory configuration for each processor must be identical. For example, if you populate socket A1 for processor 1, then you must populate socket B1 for processor 2, and so on.

•Memory modules of different sizes can be mixed provided that other memory population rules are followed (for example, 2 GB and 4 GB memory modules can be mixed).

•Populate four DIMMs per processor (one DIMM per channel) at a time to maximize performance.

•If memory modules with different speeds are installed, they operate at the speed of the slowest installed memory module(s) or slower depending on system DIMM configuration.

•Populate DIMMs based on the following processor-heat sink configurations.

55