Lenovo x3650 M5 - Page 180

capacityovermemoryfrequency,3DPC(threeDIMMsperchannel)configurationisnotrecommendedsince
3DPCconfigurationforcesthememorysubsystemtorunatalowerfrequency(1600MHz).
PleaserefertotheUnderstandingandOptimizingMemoryPerformanceforIntelXeonProcessorE5-2600v3
SeriesinIBMFlexSystem,Systemx,andBladeCenterPlatformswhitepaperforthedetail.
Memorymirroredchannel
MemorymirroredchannelmodereplicatesandstoresdataontwopairsofDIMMswithintwochannels
simultaneously.
Ifafailureoccurs,thememorycontrollerswitchesfromtheprimarypairofmemoryDIMMstothebackup
pairofDIMMs.ToenablememorymirroredchannelthroughtheSetuputility,selectSystemSettings➙
Memory.Formoreinformation,see“UsingtheSetuputility”onpage46
.Whenyouusethememory
mirroredchannelfeature,considerthefollowinginformation:
•Whenyouusememorymirroredchannel,youmustinstallapairofDIMMsatatime.ThetwoDIMMsin
eachpairmustbeidenticalinsize,type,andrank(single,dual,orquad),andorganization,butnotin
speed.ThechannelsrunatthespeedoftheslowestDIMMinanyofthechannels.
•Themaximumavailablememoryisreducedtohalfoftheinstalledmemorywhenmemorymirrored
channelisenabled.Forexample,ifyouinstall64GBofmemoryusingRDIMMs,only32GBof
addressablememoryisavailablewhenyouusememorymirroredchannel.
ThefollowingdiagramliststheDIMMconnectorsoneachmemorychannel.
DIMM 3 DIMM 9 DIMM 6 DIMM 12 DIMM 2 DIMM 8 DIMM 5 DIMM 11 DIMM 1 DIMM 7 DIMM 4 DIMM 10
Microprocessor 1
Channel
CPU1
DIMM 15 DIMM 21 DIMM 18 DIMM 24 DIMM 14 DIMM 20 DIMM 17 DIMM 23 DIMM 13 DIMM 19 DIMM 16 DIMM 22
Microprocessor 2
CPU2
Figure97.Connectorsoneachmemorychannel
Thefollowingtableshowstheinstallationsequenceformemorymirroredchannelmode:
Table12.MemorymirroredchannelmodeDIMMpopulationsequence
NumberofinstalledmicroprocessorsDIMMconnectorpopulationsequence
1,4
9,12
2,5
8,11
3,6
1
7,10
168LenovoSystemx3650M5InstallationandServiceGuide