Optane DIMMs
per CPU
DRAM DIMMs
per CPU
Total capacity
per CPU
2 Socket OS
Memory
capacity
4 Socket OS
Memory
capacity
2 Socket App
Direct Optane
capacity
4 Socket App
Direct Optane
capacity
6 X 512 GB
6 X 64 GB
3456 GB
768 GB
1.5 TB
6 TB
12 TB
6 X 512 GB
6 X 128 GB
3840 GB
1.5 TB
3 TB
6 TB
12 TB
Table 53. App Direct Mode configurations (Single CPU in Dual Socket Systems)
Optane DIMMs
DRAM DIMMs
Total capacity
OS Memory capacity
App Direct Optane
capacity
1 X 128 GB
6 X 32 GB
320 GB
192 GB
128 GB
1 X 128 GB
6 X 64 GB
512 GB
384 GB
128 GB
NOTE:
There are limited configurations available for Dual Socket Serv ers with only one CPU populated.
Mode-specific guidelines
The configurations allowed depend on the memory mode selected in the System BIOS.
Table 54. Memory operating modes
Memory Operating Mode
Description
Optimizer Mode
The
Optimizer Mode
if enabled, the DRAM controllers operate
independently in the 64-bit mode and provide optimized memory
performance.
NOTE:
DCPMM supports only Optimizer mode.
Mirror Mode
The
Mirror Mode
if enabled, the system maintains two identical
copies of data in memory, and 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. This feature
provides maximum reliability and enables the system to continue
running even during a catastrophic memory failure by switching
over to the mirrored copy. The installation guidelines to enable
Mirror Mode require that the memory modules be identical in size,
speed, and technology, and they must be populated in sets of 6 per
processor.
Single Rank Spare Mode
Single Rank Spare Mode
allocates one rank per channel as a
spare. If excessive correctable errors occur in a rank or channel,
while the operating system is running, they are moved to the spare
area to prevent errors from causing an uncorrectable failure.
Requires two or more ranks to be populated in each channel.
Multi Rank Spare Mode
Multi Rank Spare Mode
allocates two ranks per channel as a
spare. If excessive correctable errors occur in a rank or channel,
while the operating system is running, they are moved to the spare
area to prevent errors from causing an uncorrectable failure.
Requires three or more ranks to be populated in each channel.
With single rank memory sparing enabled, the system memory
available to the operating system is reduced by one rank per
channel.
For example, in a dual-processor configuration with 24x 16 GB dual-
rank memory modules, the available system memory is: 3/4 (ranks/
channel) × 24 (memory modules) × 16 GB = 288 GB, and not 24
(memory modules) × 16 GB = 384 GB. For multi rank sparing, the
multiplier changes to 1/2 (ranks/channel).
98
Installing and removing syst em components
