Figure 41. Memory Population For Dual-Channel On One Branch With Sparing - Intel S7000FC4UR Technical Product Specification

BIOS Initialization
The BIOS Setup utility provides an option to enable sparing. When sparing is selected, the
BIOS attempts to enable the feature on both branches, but the actual configuration for a given
branch depends on the population of FBDIMMs on that branch.
Note: The FBDIMM rank(s) allocated for sparing do not contribute to available physical memory
since they are reserved as a backup to replace failing FBDIMM ranks. The Effective Memory
field in the BIOS Setup utility indicates this absence of memory for the sparing operation.
Spare rank

Figure 41. Memory Population for Dual-Channel on One Branch with Sparing

This configuration:
Less efficient than the dual-channel, dual-branch configuration below because the load
is all on one branch.
Minimal configuration consists of either two single-ranked FBDIMM pairs (four FBDIMMs
total) or one dual-ranked FBDIMM pair (two FBDIMMs total).
Additional FBDIMM lock-stepped pairs can be added to increase system memory as
desired.
The FBDIMM lock-stepped pair in identically numbered DIMM slots on both memory
riser boards on a branch must be identical in organization, size, and speed for dual-
channel operation.
User must set Memory RAS to Sparing in the BIOS Setup utility.
The largest lock-stepped FBDIMM rank is selected for sparing.
120
Memory
Memory
Riser
Riser
B
A
DIMM 8
DIMM 8
DIMM 7
DIMM 7
DIMM 6
DIMM 6
DIMM 5
DIMM 5
DIMM 4
DIMM 4
DIMM 3
DIMM 3
DIMM 2
DIMM 2
DIMM 1
DIMM 1
Channel 0 Channel 1
Branch 0
Intel® Chipset
Memory Controller Hub
Intel® Server System S7000FC4UR
Channel 2 Channel 3
Branch 1
Revision 1.0