Cisco UCS B420 M4 Blade Server
12
CONFIGURING the SERVER
Choose DIMMs and Memory Mirroring
Select the memory configuration and whether or not you want the memory mirroring option.
The supported memory DIMMs and the mirroring option are listed in
When memory mirroring is enabled, the memory subsystem simultaneously writes identical data
to two adjacent channels. If a memory read from one of the channels returns incorrect data due
to an uncorrectable memory error, the system automatically retrieves the data from the other
channel. A transient or soft error in one channel does not affect the mirrored data, and
operation continues unless there is a simultaneous error in exactly the same location on a DIMM
and its mirrored DIMM. Memory mirroring reduces the amount of memory available to the
operating system by 50% because only one of the two populated channels provides data.
Notes
■
DIMM configuration rules:
— The minimum configuration is 1 DIMM per CPU
— The order in which DIMMs must be installed in a channel is Bank 1 (blue socket),
then Bank 2 (black socket), then Bank 3 (white socket).
— You cannot mix DIMM capacities within a bank
— You can mix DIMM capacities within a channel
Table 4 Supported DDR4 DIMMs and Memory Mirroring Option
Product ID (PID)
PID Description
Voltage
Ranks
/DIMM
2400-MHz DIMM Options
UCS-ML-1X644RV-A
64 GB DDR4-2400-MHz LRDIMM/PC4-19200 x4
1.2 V
4
UCS-ML-1X324RV-A
32GB DDR4-2400-MHz LRDIMM/PC4-19200 x4
1.2 V
4
UCS-MR-1X322RV-A
32GB DDR4-2400-MHz RDIMM/PC4-19200 x4
1.2 V
2
UCS-MR-1X161RV-A
16GB DDR4-2400-MHz RDIMM/PC4-19200 x4
1.2 V
1
2133-MHz DIMM Options
UCS-MR-1X648RU-A
64GB DDR4-2133-MHz TSV-RDIMM/PC4-17000/x4
1.2 V
8
UCS-MR-1X322RU-A
32GB DDR4-2133-MHz RDIMM/PC4-17000/x4
1.2 V
2
UCS-MR-1X162RU-A
16GB DDR4-2133-MHz RDIMM/PC4-17000/x4
1.2 V
2
UCS-MR-1X081RU-A
8GB DDR4-2133-MHz RDIMM/PC4-17000/x4
1.2 V
1
Memory Mirroring Option
N01-MMIRROR
Memory mirroring option
