IBM System x3400 M3 Types 7378 Installation And User Manual

Also see for System x3400 M3 Types 7378: Problem determination and service guide Brochure Installation and user guide Product guide Product guide

Contents

Independent channel modeThe server requires at least one installed DIMM. The server comes with a minimumof two 1 GB DIMMs, installed in connectors 3 and 6. Connector 3 (in channel 0)and connector 6 (in channel 1) are the farthest connectors from microprocessor 1 inthose channels. When you install additional DIMMs, install them in the order shownin Table 7, to maintain server performance.Note:v Memory sparing is only available for Intel Xeon 5600 series microprocessor.v If you have configured the server to use memory mirroring or sparing, do not usethe order shown in this table; use the installation order that is shown in Table 9on page 85.v If you install a ServeRAID-M1015 SAS/SATA adapter, make sure at least 2 GB ofmemory is installed in the server before you run DSA from a bootable CD.Table 7. DIMM installation sequence for independent channel modeInstalled microprocessors DIMM connector population sequenceMicroprocessor 1 3, 6, 8, 2, 5, 7, 1, 4Microprocessor 1 and Microprocessor 2 3, 11, 6, 14, 8, 16, 2, 10, 5, 13, 7, 15, 1, 9,4, 12Memory-mirroring modeMemory-mirroring mode replicates and stores data on two pairs of DIMMs withintwo channels simultaneously. If a failure occurs, the memory controller switchesfrom the primary pair of memory DIMMs to the backup pair of DIMMs. You mustenable memory mirroring through the Setup utility. For details about enablingmemory mirroring, see “Using the Setup utility” on page 102. When you use thememory-mirroring feature, consider the following information:v When you use memory mirroring, you must install a pair of DIMMs at a time.One DIMM must be in channel 0, and the mirroring DIMM must be in the sameconnector in channel 1. The two DIMMs in each pair must be identical in size,type, rank (single or dual), and organization. They do not have to be identical inspeed. The channels run at the speed of the slowest DIMM in any of thechannels. See Table 9 on page 85 for the DIMM connectors that are in each pair.v Channel 2, DIMM connectors 7, 8, 15, and 16 are not used in memory-mirroringmode.v The maximum amount of available memory is reduced to half of the amount ofinstalled memory when memory mirroring is enabled. For example, if you install64 GB of memory, only 32 GB of addressable memory is available when you usememory mirroring.The following illustration shows the memory channel interface layout with the DIMMinstallation sequence for memory-mirroring mode. The numbers within the boxesindicate the DIMM population sequence in pairs within the channels, and thenumbers next to the boxes indicate the DIMM connectors within the channels. Forexample, the following illustration shows that the first pair of DIMMs (indicated by 1sinside the boxes) should be installed in DIMM connector 3 on channel 0 and DIMMconnector 6 on channel 1. DIMM connectors 7, 8, 15, and 16 on channel 2 are notused in memory-mirroring mode.84 IBM System x3400 M3 Types 7378 and 7379: Installation and User's Guide