Dell 2950 Non-Optimal Memory Configurations, Memory Sparing Support, Memory Mirroring Support

Non-Optimal Memory Configurations

System performance can be affected if your memory configuration does not conform to the preceding installation guidelines. Your system may issue an error message during startup stating that your memory configuration is non-optimal.

Memory Sparing Support

The system supports memory sparing if eight identical memory modules are installed in the system. The memory sparing feature must be enabled in the System Setup program and can be used only if memory mirroring is not enabled.

Memory sparing allocates four ranks of DIMM memory to the spare bank. These four ranks consist of the first rank of memory in DIMM sockets 1 through 4. For single-rank DIMMs, the entire capacity of the four DIMMs is allocated to sparing whereas for dual-rank DIMMs, only half of the four-DIMM capacity is allocated to sparing. Table 3-2 shows how memory sparing splits the available and spared memory in each of the single- and dual-ranked memory module combinations.

Table 3-2. Memory Sparing Configurations

DIMMs	Size/Type	Total Memory	Available	Spare
8	256-MB single-rank	2 GB	1 GB	1 GB
	512-MB single-rank	4 GB	2 GB	2 GB
	1-GB single-rank	8 GB	4 GB	4 GB
	2-GB single-rank	16 GB	8 GB	8 GB
	2-GB dual-rank	16 GB	12 GB	4 GB
	4-GB dual-rank	32 GB	24 GB	8 GB

Memory Mirroring Support

The system supports memory mirroring if eight identical memory modules are installed in the system. Mirroring must be enabled in the System Setup program and can be used only if memory sparing is not enabled. In a mirrored configuration, the total available system memory is one-half of the total installed memory.

Installing Memory Modules

CAUTION: Only trained service technicians are authorized to remove the system cover and access any of the components inside the system. See your Product Information Guide for complete information about safety precautions, working inside the computer, and protecting against electrostatic discharge.

1Turn off the system, including any attached peripherals, and disconnect the system from the electrical outlet.

2Open the system. See "Opening the System" on page 54.

3Remove the memory cooling shroud. See "Removing the Cooling Shroud" on page 67.

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Installing System Components