This 32GB memory is 100% compatible with the Dell XC720xd. Our memory team will be happy to help you choose the right memory and configure your server.TechnologyRAM in maximum capacityMaximum possible memory configuration (for 2 CPUs with 12 slots each)UDIMM ECC128GB RAM 2 x (8 x 8GB ECC UDIMM)RDIMM 2Rank384GB RAM 2 x (12 x 16GB RDIMM)RDIMM 4Rank512GB RAM 2 x (8 x 32GB RDIMM)LRDIMM1.5TB RAM 2 x (12 x 64GB LRDIMM)ECC DIMM, Registered DIMM and Load Reduced LRDIMM memory modules may not be mixed.not be mixed. When upgrading, you should therefore know which memories are already present or upgrade completely to RDIMM memory.Memory configuration principlesThere are 4 memory channels per CPU, each with 2 memory slotsWhen using ECC UDIMM or 4Rank (4Rx..) RDIMM memories, only 2 of 3 memory slots per memory channel can be occupiedECC DIMM, Registered DIMM and Load Reduced LRDIMM memory modules must not be mixedMemory slots for which no processor is available must not be populatedMemory configuration for good system performanceDistribute the memory evenly across the memory slots and evenly across the CPUsIf more than one CPU is present, the memory per CPU should be configured identically (mirrored to the other CPU).