Dell Certified Memory – mixing various kinds of DDR3 memory
To address recent enquiries around installing and upgrading DDR3 memory, below you can a find some useful guidelines for mixing various kinds of DDR3 memory (rank, capacity, speed, voltage & vendor).
|Mixed Type (RDIMM / UDIMM)||NO||Not Supported|
|Mixed Ranks||YES||Single (1R) and Dual Rank (2R) DIMMs can be mixed. If mixing 1R or 2R with Quad Rank (4R) DIMMs, the first slot of each channel populated (first two white tab DIMM slots on each processor: A1, A2, B1 & B2) must be populated with the 4R DIMM. Only two 4R DIMMs are permitted per channel because the maximum of total ranks per channel is 8.|
|Mixed Capacity||YES||All populated channels must have the same DIMM arrangement. Example with Channel 1: if bank A is populated with a 4GB DIMM (slot A1), bank B with 2GB (slot A4) and Bank C is empty (slot A7), all memory Channels must be populated that way.|
|Mixed Speeds||YES||If memory modules (DIMMS) with different speeds are installed, all DIMMs will operate at the speed of the slowest installed DIMM.
Also, if any DIMMS (regardless of speed) are installed in the third bank (bank C: slots A/B 7, 8 or 9), the maximum system memory speed will be 800MHz. This is the current maximum frequency supported by Intel and Dell, when DIMMS are installed in slots 7, 8 & 9.
|Mixed Voltage||YES||If memory modules (DIMMS) with different voltage are installed, all DIMMs will operate at the voltage of the DIMM that has the highest voltage.
All DDR3 LV DIMMs are backwards compatible with 1.5V. They can be placed in any system that cannot operate at 1.35V and will still work at standard voltage
|Mixed Vendors||YES||Any Dell sourced DDR3 DIMMs are supported, regardless of vendor or vendor mix. Where possible, Dell recommends using the same DIMM manufacturer.|
Please use the general rule of thumb when mixing memory modules with different ranks, speed or voltage:
- · highest capacities first
- · highest ranks first
- · SV first, then LV