5
Memory
The PowerEdge R740xd2 supports up to 16 DIMMs, with up to 512GB of memory and speeds of up to 2666MT/s.
Supported memory
The table below lists the memory technologies supported by the PowerEdge R740xd2:
Table 1. Supported memory technologies
Features
Description
DIMM types
RDIMM
Transfer speed
2666MT/s
2400MT/s
2133MT/s
1866MT/s
Voltage
1.2V (DDR4)
Memory speed
The PowerEdge R740xd2 support memory speeds of 2666MT/s, 2400MT/s, 2133MT/s, and 1866MT/s depending on the DIMM
types installed and the configuration. All memory on all processors and channels run at the same speed and voltage. By default, this
speed will be the highest common supported speed between the CPUs and DIMMs. The operating speed of the memory is also
determined by the maximum speed supported by the processor, speed settings in BIOS, and operating voltage of the system.
The following table lists the memory configuration and performance details based on the quantity and type of DIMMs per memory
channel:
Table 2. DIMM performance details
DIMM type
DIMM ranking
Capacity
DIMM rated voltage, speed
RDIMM
1R / 2R
8GB, 16GB, 32GB
DDR4 (1.2V), 2666
Memory configurations
The PowerEdge R740xd2 servers support flexible memory configurations ranging from capacities of 8GB(minimum) to
512GB(maximum). CPU1 support up to 10 DIMMs sand CPU2 support up to 6 DIMMs.
Both systems support a flexible memory configuration, according to the following population 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 is allowed per system: RDIMM.
•
DIMMs with different data widths (x4 and x8) can be mixed.
•
Can mix DIMMs with different capacities.
– Population rules require the largest capacity DIMM be placed first (slot A1 populated first, then A2, and so on. The second
CPU mirrors the first CPU population).
15