Appendix B: Memory configuration
174
Dual-ranked memory sparing
When a dual-ranked FBDIMM is used as spare, the BIOS can
independently select a physical rank on that FBDIMM as the spare unit
and utilize the other physical rank as a normal unit. This selective
sparing ensures maximization of available memory while still providing
RAS.
Note: Populating differently ranked FBDIMMs for sparing is not a
good practice and may yield unpredictable results.
To configure memory to memory sparing mode:
1 Run BIOS setup. See “Entering BIOS setup” on page 100.
2 Use the up and down arrow keys to select the Advanced menu.
3 Use the up and down arrow keys to select Memory
Configuration, then press Enter. The Memory Configuration
menu appears.
4 Use the up and down arrow keys to select Memory RAS and
Performance Configuration, then press Enter. The Memory RAS
and Performance Configuration menu appears.
5 Set the Select Memory RAS Configuration to Sparing.
6 Return to the Memory Configuration menu option.
• Make sure Current Configuration indicates Dual-DIMM
Sparing Mode. If the option indicates Current Memory
Configuration, you may need to install more memory to
meet the requirements of the selected configuration.
• Make sure that Memory Sparing Possible indicates Yes.
7 Press F10 to save changes and exit.
8 Press Y to confirm. The server reboots to activate the changes.
