Dell T605, DR715 owner manual 129, CPU CPUs 512 16 GB

channel. For dual-rank DIMMs, two DIMMs are also required for sparing, but as only the first rank of each DIMM is allocated, only half of a dual-rank DIMM’s capacity is allocated for sparing. The second ranks on both DIMMs are available memory.

Memory sparing calculates the appropriate DIMMs to spare by searching the DIMM sockets, starting with the higher-numbered socket pair (specifically, sockets A3 and A4 or sockets B3 and B4), for an amount of memory large enough to spare one of the available channels of memory. If the DIMMs in these sockets are sufficient to spare a channel of the available memory, the first rank of each of those two DIMMs are spared. If the amount of memory is not large enough to spare an available memory channel, the system spares the DIMM ranks in the lower-numbered sockets. Table 3-2 shows how memory sparing works in various memory configurations.

Table 3-2. Memory Sparing in Single- and Dual-Processor Configurations

								Available	Spared
	Processor 1				Processor 2			Memory	Memory
DIMM	DIMM	DIMM	DIMM	DIMM	DIMM	DIMM	DIMM	1 CPU /	1 CPU /
A1	A2	A3	A4	B1	B2	B3	B4	2 CPUs	2 CPUs
512	512	512	512	512	512	512	512	1 GB /	1 GB /
MB	MB	MB	MB	MB	MB	MB	MB	2 GB	2 GB
1 GB	1 GB	1 GB	1 GB	1 GB	1 GB	1 GB	1 GB	2 GB /	2 GB /
								4 GB	4 GB
2 GB	2 GB	2 GB	2 GB	1 GB	1 GB	1 GB	1 GB	4 GB /	2 GB /
								8 GB	4 GB
2 GB	2 GB
		2 GB	2 GB	2 GB	2 GB	2 GB	2 GB	4 GB /	2 GB /
								8 GB	4 GB
4 GB	4 GB	4 GB	4 GB	4 GB	4 GB	4 GB	4 GB	8 GB /	4 GB /
								16 GB	8 GB

Indicates a spared single-rank DIMM (512-MB, 1-GB, or 2-GB). The entire capacity of this DIMM is reserved for sparing.

Indicates a spared dual-rank DIMM (2-GB and higher). One-half of this DIMM’s capacity is reserved for sparing.

Installing System Components

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