Hardware options installation 36
Certain performance features are unique with HP SmartMemory. HP SmartMemory 1.35V DDR3-1333
Registered memory is engineered to achieve the same performance level as 1.5V memory. For example,
while the industry supports DDR3-1333 RDIMM at 1.5V, this Gen8 server supports DDR3-1333 RDIMM up
to 3 DIMMs per channel at 1066 MT/s running at 1.35V. This equates to up to 20% less power at the DIMM
level with no performance penalty. In addition, the industry supports UDIMM at 2 DIMMs per channel at
1066 MT/s. HP SmartMemory supports 2 DIMMs per channel at 1333 MT/s, or 25% greater bandwidth.
Memory subsystem architecture
The memory subsystem in this server is divided into channels. Each processor supports four channels, and
each channel supports three DIMM slots, as shown in the following table.
•
Processor 1
Channel
Population order
Slot number
1
A
E
I
1
2
3
2
B
F
J
4
5
6
3
C
G
K
12
11
10
4
D
H
L
9
8
7
•
Processor 2
Channel
Population order
Slot number
3
C
G
K
1
2
3
4
D
H
L
4
5
6
1
A
E
I
12
11
10
2
B
F
J
9
8
7
For the location of the slot numbers, see "DIMM slots (on page
)."
This multi-channel architecture provides enhanced performance in Advanced ECC mode. This architecture
also enables Lockstep and Online Spare Memory modes. This server supports RDIMMs and UDIMMs.
DIMM slots in this server are identified by number and by letter. Letters identify the population order. Slot
numbers indicate the DIMM slot ID for spare replacement.
