Dell PowerEdge C6420 RAM Upgrade

What Types of RAM Are Supported in the Dell PowerEdge C6420?

• The Dell PowerEdge C6420 supports RDIMM (Registered DIMMs) and LRDIMM (Load-Reduced DIMMs).

Which Memory Speeds Are Compatible With the Dell PowerEdge C6420?

• The server supports DDR4-2133, DDR4-2400, DDR4-2666, DDR4-2933, DDR4-3200 (will clock down).
• Keep in mind that if different speeds are mixed, all modules operate at the slowest DIMM speed.

What Is the Maximum Supported RAM Capacity for the Dell PowerEdge C6420?

• Up to 512GB (16 × 32GB) with RDIMMs.
• Up to 2TB (16 × 128GB) with LRDIMMs.

How do I achieve the best performance for my Dell PowerEdge C6420?

• Populate DIMMs evenly across all channels and use the highest supported speed compatible with your CPU.

What is RDIMM and LRDIMM?

• RDIMM (Registered DIMM): Registered DIMMs are memory modules with an additional register between the memory controller and the DRAM. This register reduces the electrical load on the memory controller, allowing for better stability and scalability in servers. RDIMMs are commonly used in environments that require high reliability and performance.
• LRDIMM (Load-Reduced DIMM): Load-Reduced DIMMs replace the register found in RDIMMs with an on-board memory buffer, further reducing the electrical load on the memory controller. This enables servers to support higher memory capacities compared to RDIMMs. LRDIMMs are ideal for applications requiring maximum memory density and performance.

General DIMM Population Guidelines for Dell PowerEdge C6420

• Do Not Mix RDIMMs and LRDIMMs
• If mixing memory speeds, all DIMMs will operate at the lowest speed.
• Install DIMMs starting furthest from the processor.
• Populate DIMMs evenly across all channels.
• Ensure all CPUs have memory installed for their DIMM slots to function.

Dell PowerEdge C6420 Memory Installation Steps

• Power Off the server and disconnect it from power.
• Wear ESD Gear: Use an ESD wrist strap and work in an ESD-safe environment.
• Open the server and locate the DIMM slots.
• Inspect the slots for dust or debris and ensure proper alignment of the DIMMs.
• Follow the DIMM population order in the server manual.
• Firmly insert DIMMs until they click. Avoid using excessive force.
• Close the server and reconnect power.
• Verify the memory configuration in the BIOS.