Table 7. Memory mirrored channel mode DIMM population sequence (continued)Number of DIMMsNumber of installedmicroprocessor DIMM connectorSeventh pair of DIMMs 2 13, 16Eighth pair of DIMMs 2 21, 24Ninth pair of DIMMs 2 14, 17Tenth pair of DIMMs 2 20, 23Eleventh pair of DIMMs 2 19, 22Twelfth pair of DIMMs 2 15, 18Note: DIMM connectors 3, 6, 7, 10, 15, 18, 19, and 22 are not used in memory mirroredmode when UDIMMs are installed in the server.When you install or remove DIMMs, the server configuration information changes.When you restart the server, the system displays a message that indicates that thememory configuration has changed.Memory rank sparingSparing enables a failing rank to be replaced by ranks installed in an unoccupiedspace. An unused spare rank on the channel can be used to copy the contents of afailing rank on that channel. You can enable rank sparing memory in the Setuputility, select System Settings → Memory. For more information, see “Using theSetup utility” on page 120.The following diagram lists the DIMM connectors on each memory channel.You can install DIMMs for the microprocessor 2 once the microprocessor 2 isinstalled. You do not need to wait until all of the DIMM connectors formicroprocessor 1 are filled. The following table shows the installation sequence formemory rank sparing mode:Table 8. Memory rank sparing mode DIMM population sequenceNumber of DIMMsNumber of installedmicroprocessor DIMM connectorFirst pair of DIMMs 1 1, 2Second pair of DIMMs 1 4, 5Third pair of DIMMs 1 8, 9Fourth pair of DIMMs 1 11, 12Fifth pair of DIMMs 1 7, 10Sixth pair of DIMMs 1 3, 6Seventh pair of DIMMs 2 13, 14Figure 14. Connectors on each memory channel82 IBM System x3500 M4 Type 7383: Installation and User’s Guide
