Depending on the processor model, the number of DIMMs installed, and whether UDIMMs or RDIMMs
are installed, the memory clock speed may be reduced to 1066 or 800 MHz. For more information on
the effect of DIMM slot
population, see "
General DIMM slot population guidelines (on page 21)."
pports three channels,
Memory subsystem architecture
The memory subsystem in this server is divided into channels. Each processor su
and each channel supports two DIMM slots, as shown in the following table.
Channel Slot Slot number
1 D
A
1
2
2 E
B
3
4
3 F
C
5
6
This multi-channel architecture provides enhanced performance in Advanc
also enables the Mirrored Memory and Lockstep memory modes. This server su
ed ECC mode. This architecture
pports both Registered
IM s) and U DIMMs (UDIMMs).
M s this server are identified by number and by letter. Letters identify the slots to populate for
c modes. Slot nu ed by ROM messages during boot and for error reporting.
Single-, dual-, and quad-rank DIMMs
To understand and configure memory protection modes properly, an understanding of single-, dual-, and
d-ra lpful. ration requirements are based on these classifications.
A single-rank DIMM has one s that is accessed while writing to or reading from the
k DIMM single-rank DIMMs on the same module, with only
one rank accessible at a tim two dual-rank DIMMs on the same
one rank is accessible at a time. The server memory control subsystem selects the proper
e the greatest capacity with the existing memory technology. For
logy supports 2-GB single-rank DIMMs, a dual-rank DIMM would be 4-
ld be 8-GB.
DIMM id
PC3 D Ms (RDIMM nbuffered
DIM lots in
specifi AMP mbers are report
qua nk DIMMs is he Some DIMM configu
set of memory chip
memory. A dual-ran is similar to having two
e. A quad-rank DIMM is, effectively,
module. Only
rank within the DIMM when writing to or reading from the DIMM.
Dual- and quad-rank DIMMs provid
example, if current DRAM techno
GB, and a quad-rank DIMM wou
entification
IMPORTANT: This server does not support mixing RDIMMs and UDIMMs. Attempting to mix
these two types causes the server to halt during BIOS initialization.
Hardware options installation 19
