Hardware options installation  53 
The memory subsystem in this server can support LRDIMMs or RDIMMs: 
•  RDIMMs offer lower latency in one DIMM per channel configurations and (relatively) low power 
consumption. They 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. 
All types are referred to as DIMMs when the information applies to all types. When specified as LRDIMM or 
RDIMM, 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 
•  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 capacity  DIMM rank  Native speed (MT/s)  Voltage 
RDIMM 
4 GB  Single-rank  1600  STD 1.5 V 
RDIMM 
4 GB  Single-rank  1333  LV 1.35 V 
RDIMM 
4 GB  Single-rank  1333  ULV 1.25 V 
RDIMM 
8 GB  Single-rank  1600  STD 1.5 V 
RDIMM 
8 GB  Dual-rank  1333  LV 1.35 V 
RDIMM 
8 GB  Dual-rank  1333  ULV 1.25 V 
RDIMM 
16 GB  Dual-rank  1600  STD 1.5 V 
RDIMM 
16 GB  Dual-rank  1333  LV 1.35 V 
LRDIMM 
32 GB  Quad-rank  1333  LV 1.35 V 
 
Depending on the processor model, the number of DIMMs installed, and the voltage(s) of the DIMMs 
installed, the memory clock speed can be reduced from the DIMMs' native speed. See the following tables 
for details. 
Populated DIMM speed (MT/s), RDIMM 
 
Memory 
modules 
per 
channel 
Single-rank 
or 
Dual-rank 
Memory module 
native speed 
Memory bus 
speed (standard 
voltage memory 
module) 
Memory bus 
speed (low 
voltage memory 
module) 
Memory bus 
speed (ultra low 
voltage memory 
module) 
1 
1  1600 MHz  1600 MHz  1333 MHz  1333 MHz 
1 
1  1333 MHz  1333 MHz  1333 MHz  1333 MHz 
2 
2 Single-rank  1600 MHz 
1333 MHz 
1333 MHz  1333 MHz  1333 MHz 
2 
2 Dual-rank  1600 MHz 
1333 MHz 
1333 MHz  1333 MHz  1066 MHz 
2 
1333 MHz 
3 
3 Single-rank  1600 MHz  
1333 MHz 
1066 MHz  1066 MHz  800 MHz 
3 
3 Dual-rank  1600 MHz 
1333 MHz 
1066 MHz  800 MHz  667 MHz