Owners Manual

NOTE: Memory sparing does not offer protection against a multi-bit uncorrectable error.
Memory mirroring
Memory mirroring offers the strongest memory module reliability mode, providing improved uncorrectable multi-bit failure
protection. In a mirrored configuration, the total available system memory is one half of the total installed physical memory.
Half of the installed memory is used to mirror the active memory modules. In the event of an uncorrectable error, the system
switches over to the mirrored copy. This ensures Single Device Data Correction (SDDC) and multi-bit protection.
The installation guidelines for memory modules are as follows:
● Memory modules must be identical in size, speed, and technology.
● Memory modules must be populated in sets of 6 per CPU to enable memory mirroring.
Table 8. Memory population rules
Processor Configuration Memory population Memory population information
Single CPU Optimizer (Independent
channel) population order
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 Populate in this order, odd amount
allowed.
Mirror population order {1, 2, 3, 4, 5, 6}, {7, 8, 9, 10, 11,
12}
Mirroring is supported with 6 or 12
DIMM slots per CPU.
Single rank spare population
order
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 Populate in this order, odd amount
allowed. Requires two ranks or
more per channel.
Multi rank spare population
order
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 Populate in this order, odd amount
allowed. Requires three ranks or
more per channel.
Fault resilient population order {1, 2, 3, 4, 5, 6}, {7, 8, 9, 10, 11,
12}
Supported with 6 or 12 DIMM slots
per CPU.
Dual CPU (Starting
with CPU1, CPU1
and CPU2 population
should match)
Optimized (Independent
channel) population order
C1{1}, C2{1}, C1{2}, C2{2},
C1{3}, C2{3}...
Odd amount of DIMM slots per
CPU allowed.
Mirroring population order C1{1, 2, 3, 4, 5, 6}, C2{1, 2, 3,
4, 5, 6}, C1{7, 8, 9, 10, 11, 12},
C2{7, 8, 9, 10, 11, 12}
Mirroring is supported with 6 or 12
DIMM slots per CPU.
Single rank sparing population
order
C1{1}, C2{1}, C1{2}, C2{2},
C1{3}, C2{3}...
Populate in this order, odd amount
per CPU allowed. Requires two
ranks or more per channel.
Multi rank spare population
order
C1{1}, C2{1}, C1{2}, C2{2},
C1{3}, C2{3}, C1{4}, C2{4},
C1{5}, C2{5}...
Populate in this order, odd amount
per CPU allowed. Requires three
ranks or more per channel.
Fault resilient population order C1{1, 2, 3, 4, 5, 6}, C2{1, 2, 3,
4, 5, 6}, C1{7, 8, 9, 10, 11, 12},
C2{7, 8, 9, 10, 11, 12}
Supported with 6 or 12 DIMM slots
per CPU.
Removing a memory module
Prerequisites
1. Follow the safety guidelines listed in Safety instructions.
2. Follow the procedures in Before working inside your system.
3. If applicable, remove the air shroud.
4. If applicable, remove the mid drive tray.
WARNING:
Allow the memory modules to cool after you power off the system. Handle the memory modules by
the card edges and avoid touching the components or metallic contacts on the memory module.
82 Installing and removing system components