Dell PowerEdge M420 Systems Owner's Manual

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:

• x4 and x8 DRAM based DIMMs can be mixed. For more information, see Mode-Specific Guidelines.
• Populate DIMM sockets only if a processor is installed. For single-processor systems, sockets A1 to A3 are available. For dual-processor systems, sockets A1 to A3 and sockets B1 to B3 are available.
• In a dual-processor configuration, the memory configuration for each processor must be identical. For example, if you populate socket A1 for processor 1, then 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).
• If memory modules with different speeds are installed, they will operate at the speed of the slowest installed memory module(s) or slower depending on system DIMM configuration.