Dell PowerEdge R420 Technical Guide - Page 18

The R420 supports the DIMMs listed in Table 8. For the latest information on supported memory, visit Dell.com. Table 8. DIMMs supported Capacity (GB) Speed (MT/s) Type Ranks per Data DIMM width SDDC support Voltage 2 1600 UDIMM 4 1600 RDIMM 2 1333 RDIMM 2 1600 RDIMM 4 1333 RDIMM 4 1333 RDIMM 4 1600 RDIMM 8 1333 RDIMM 8 1600 RDIMM 16 1333 RDIMM 16 1600 RDIMM 32 1333 RDIMM 1 x8 Advanced ECC 1.35 2 x8 Advanced ECC 1.35 1 x8 Advanced ECC 1,35 1 X8 Advanced ECC 1.35 2 x8 Advanced ECC 1.35 1 x4 All modes 1.35 2 x8 Advanced ECC 1.35 2 x4 All modes 1.35 2 x4 All modes 1.35 2 x4 All modes 1.35 2 x4 All modes 1.35 4 x4 All modes 1.35 Memory configurations Flexible memory configurations are supported on the R420, ranging from capacities of 2GB to 384GB. The system supports up to 6 DIMMs per processor (up to 12 DIMMs in a 2- processor configuration). The R420 has 3 memory channels per processor, with each channel supporting up to 2 DIMMs. The R420 supports a flexible memory configuration according to these basic rules: • Speed: If DIMMs of different speeds are mixed, all channels across all processors operate at the slowest DIMM's common frequency. • DIMM type: Only one type of DIMM can be used in a system. UDIMMs and RDIMMs cannot be mixed. The following additional memory population guidelines apply to the R420: • Up to two quad- rank (QR), dual- rank (DR), or single- rank (SR) DIMMs may be populated per channel. • DIMMs must be installed in each channel, starting with the DIMM farthest from the processor. • DIMMs should be installed with largest rank count to smallest. For example, if DR DIMMS are mixed with SR DIMMs, DR DIMMS should be placed in the lowest DIMM slots, followed by the SR DIMMs. For more information on memory configuration, see the Dell PowerEdge R420 Systems Owner's Manual on Support.Dell.com/Manuals. 18 PowerEdge R420 Technical Guide