Hardware options installation 41
• UDIMMs represent the most basic type of memory module and offer lower latency in one DIMM per
channel configurations and (relatively) low power consumption, but are limited in capacity.
• RDIMMs offer larger capacities than UDIMMs and include address parity protection.
• LRDIMMs support higher densities than single- and dual-rank RDIMMs, and higher speeds than
quad-rank RDIMMs. This support enables you to install more high capacity DIMMs, resulting in higher
system capacities and higher bandwidth.
• HDIMMs provide faster speeds than other DIMMs. 12 DIMMs per processor are required with
HDIMMs.
IMPORTANT: LRDIMMs are not supported with the 10 SFF drive cage.
All types are referred to as DIMMs when the information applies to all types. When specified as LRDIMM,
RDIMM, DIMM, or HDIMM, the information applies to that type only. All memory installed in the server must
be the same type.
The server supports the following DIMM speeds:
• Single- and dual-rank PC3-10600 (DDR-1333) RDIMMs operating at up to 1333 MT/s
• Single- and dual-rank PC3-12800 (DDR-1600) RDIMMs operating at up to 1600 MT/s
• Single- and dual-rank PC3-10600 (DDR-1333) UDIMMs operating at up to 1333 MT/s
• Quad-rank PC3L-10600 (DDR3-1333) LRDIMMs, operating as dual-rank DIMMs, at up to 1333 MT/s
Speed, voltage, and capacity
DIMM type DIMM rank DIMM capacity Native speed (MT/s) Voltage
RDIMM
Dual-rank 8 GB 1333 LV
RDIMM
Single-rank 8 GB 1600 STD
RDIMM
Dual-rank 16 GB 1333 LV
LRDIMM
Quad-rank 32 GB 1333 LV
UDIMM
Dual-rank 8 GB 1333 LV
HDIMM
Dual-rank 16 GB 1333 STD
Depending on the processor model, the number of DIMMs installed, and whether LRDIMMs, UDIMMs,
RDIMMs, or HDIMMs are installed, the memory clock speed can be reduced to 1333 or 1066 MT/s.
Populated DIMM speed (MT/s)
DIMM type DIMM rank 1 DIMM per channel 2 DIMMs per channel 3 DIMMs per channel
RDIMM
Dual-rank (8 GB) 1333 1333 1066
1
RDIMM
Single-rank (8 GB) 1600 1600 1066
RDIMM
Dual-rank (16 GB) 1333 1333 1066
1
LRDIMM
Quad-rank (32
GB)
1333
2
1333
2
1066
UDIMM
Dual-rank (8 GB) 1333
3
1333
3
—
HDIMM
Dual-rank (16 GB) N/A N/A 1333
4
1
RDIMM supports 1.35V 3DPC at 1066, using HP SmartMemory. Third-party memory supports 1.5V 3DPC at 1066
MT/s.
2
HP SmartMemory LRDIMM supports 1.35V or 1.5V 1DPC or 2 DPC at 1333 MT/s. Third-party memory supports 1.5V
1DPC or 2DPC at 1333 MT/s, or 1.35V 1DPC or 2DPC at 1066 MT/s.