Install The 2.5-Inch-Drive Backplane - Lenovo ThinkSystem SR550 Setup Manual

Rank sparing mode
In rank sparing mode, one rank of a memory module works as the spare rank for the other ranks on the same
channel. The spare rank is not available as system memory.
Notes:
• All memory modules to be installed must be the same type with the same capacity, frequency, voltage,
and number of ranks.
• Single-rank memory modules do not support rank sparing mode.
Table 15. Rank sparing mode with one processor
Total memory
modules
6
1
2
3
4
5
6
6
The following table shows the memory module population sequence for rank sparing mode when two
processors (CPU1 and CPU2) are installed.
Table 16. Rank sparing mode with two processors
Total
memory
mod-
12 11
ules
2
3
4
5
6
7
11
8
11
9
11
10
11
11
12 11
12

Install the 2.5-inch-drive backplane

Use this information to install the 2.5-inch-drive backplane. This topic applies only to server models that
support 2.5-inch-drive backplanes.
Processor 1
5 4
4
4
5 4
5 4
5 4
Processor 2
10 9 8
9
9
10 9
10 9
10 9 8
10 9 8
10 9 8
10 9 8
10 9 8
10 9 8
10 9 8
3
3
3
3
3
3
3
Processor 1
7 6 5 4
4
4
4
4
5 4
5 4
5 4
7 5 4
7 6 5 4
7 6 5 4
Total memory
modules
2 1
2
2
2 1
2 1
memory
3 2 1
modules
3
3
3
3 2
3 2
3 2
3 2
3 2 1
3 2 1
3 2 1
3 2 1
.
Chapter 3 Server hardware setup
1
2
3
4
5
6
Total
2
3
4
5
6
7
8
9
10
11
12
61