Lenovo System x3550 M5 - Page 178

•Whenyouusememorymirroredchannel,youmustinstallapairofDIMMsatatime.ThetwoDIMMsin
eachpairmustbeidenticalinsize,type,andrank(single,dual,orquad),andorganization,butnotin
speed.ThechannelsrunatthespeedoftheslowestDIMMinanyofthechannels.
•Themaximumavailablememoryisreducedtohalfoftheinstalledmemorywhenmemorymirrored
channelisenabled.Forexample,ifyouinstall64GBofmemoryusingRDIMMs,only32GBof
addressablememoryisavailablewhenyouusememorymirroredchannel.
ThefollowingdiagramliststheDIMMconnectorsoneachmemorychannel.
Figure87.Connectorsoneachmemorychannel
Thefollowingtableshowstheinstallationsequenceformemorymirroredchannelmode:
Table28.MemorymirroredchannelmodeDIMMpopulationsequence
DIMMs
Numberofinstalled
microprocessors
DIMMconnectorpopulation
sequenceonthesystemboard
OneMicroprocessor
1stset11,4
2ndset19,12
3rdset12,5
4thset18,11
5thset13,6
6thset17,10
TwoMicroprocessors
1stset21,4
2ndset213,16
3rdset29,12
4thset221,24
5thset22,5
6thset214,17
7thset28,11
8thset220,23
9thset23,6
10thset215,18
11thset27,10
12thset219,22
164LenovoSystemx3550M5InstallationandServiceGuide