Memory Rank Sparing - IBM System x3650 M4 Type 7915 Installation And User Manual

Memory rank sparing

The memory rank sparing feature disables the failed memory from the system
configuration and activates a rank sparing DIMM to replace the failed active DIMM.
You can enable rank sparing memory in the Setup utility, select System Settings →
Memory. For more information, see "Using the Setup utility" on page 145. When
you use the memory rank sparing feature, consider the following information:
v The memory rank sparing feature is supported on server models with an Intel
v The maximum available memory is reduced when memory rank sparing mode is
The following diagram lists the DIMM connectors on each memory channel.
Figure 2. Connectors on each memory channel
Follow the installation sequence for rank sparing mode:
v Install at least one quad-rank DIMM in a channel.
v Install at least two single-rank or dual-rank DIMMs in a channel.
You can install DIMMs for the microprocessor 2 once the microprocessor 2 is
installed. You do not need to wait until all of the DIMM connectors for
microprocessor 1 are filled. The following table shows the installation sequence for
memory rank sparing mode:
112
System x3650 M4 Type 7915: Installation and User's Guide
™
Xeon 5600 series microprocessor.
enabled.
Microprocessor 2
Ch2 Ch3
CPU2
Table 10. Memory rank sparing mode DIMM population sequence
Number of DIMMs
First pair of DIMMs
Second pair of DIMMs
Third pair of DIMMs
Fourth pair of DIMMs
Fifth pair of DIMMs
Sixth pair of DIMMs
Seventh pair of DIMMs
Eighth pair of DIMMs
Ninth pair of DIMMs
Tenth pair of DIMMs
Eleventh pair of DIMMs
Twelfth pair of DIMMs
Note: DIMM connectors 3, 6, 7, 10, 15, 18, 19, and 22 are not used in memory rank
sparing mode when UDIMMs are installed in the server.
CH1 CH0 Ch2 Ch3
Number of installed
microprocessor
1
1
1
1
1
1
2
2
2
2
2
2
Microprocessor 1
CH1 CH0
CPU1
DIMM connector
1, 2
4, 5
8, 9
11, 12
7, 10
3, 6
13, 14
16, 17
20, 21
23, 24
19, 22
15, 18