Lenovo System x3500 M5 Type 5464 - DIMM Installation Sequence; Memory Mirrored Channel

DIMMinstallationsequence
Dependingontheservermodel,theservermaycomewithaminimumofone8GBor16GBDIMM
installedinslot1.WhenyouinstalladditionalDIMMs,installthemintheordershowninthefollowing
tabletooptimizesystemperformance.
Ingeneral,allfourchannelsonthememoryinterfaceforeachmicroprocessorcanbepopulatedinanyorder
andhavenomatchingrequirements.
Table7.IndependentmodeDIMMinstallationsequence
Numberofinstalled
microprocessorDIMMconnectorpopulationsequence
Onemicroprocessorinstalled
1,4,9,12,2,5,8,11,3,6,7,10
Twomicroprocessorsinstalled1,13,4,16,9,21,12,24,2,14,5,17,8,20,11,23,3,15,6,18,7,19,10,22
Foroptimalperformance:
Makesureallfourmemorychannelsofeachmicroprocessorarepopulated.Eachmemorychannelsshould
bepopulatedwiththesametypeandamountofmemoryperchannel.Eachmicroprocessorsocketshould
bepopulatedwiththesametypeandamountofmemorypersocket.1DPC(oneDIMMperchannel)or
2DPC(twoDIMMperchannel)memoryconfigurationarerecommended.Unlessthereisaneedformemory
capacityovermemoryfrequency,3DPC(threeDIMMsperchannel)configurationisnotrecommendedsince
3DPCconfigurationforcesthememorysubsystemtorunatalowerfrequency(1600MHz).
PleaserefertotheUnderstandingandOptimizingMemoryPerformanceforIntelXeonProcessorE5-2600v3
SeriesinIBMFlexSystem,Systemx,andBladeCenterPlatformswhitepaperforthedetail.
Memorymirroredchannel
MemorymirroredchannelmodereplicatesandstoresdataontwopairsofDIMMswithintwochannels
simultaneously.Ifafailureoccurs,thememorycontrollerswitchesfromtheprimarypairofmemoryDIMMs
tothebackuppairofDIMMs.
Ifafailureoccurs,thememorycontrollerswitchesfromtheprimarypairofmemoryDIMMstothebackup
pairofDIMMs.ToenablememorymirroredchannelthroughtheSetuputility,selectSystemSettings➙
Memory.Formoreinformation,see“UsingtheSetuputility”onpage107
.Whenyouusethememory
mirroredchannelfeature,considerthefollowinginformation:
•Whenyouusememorymirroredchannel,youmustinstallapairofDIMMsatatime.ThetwoDIMMsin
eachpairmustbeidenticalinsize,type,andrank(single,dual,orquad),andorganization,butnotin
speed.ThechannelsrunatthespeedoftheslowestDIMMinanyofthechannels.
•Themaximumavailablememoryisreducedtohalfoftheinstalledmemorywhenmemorymirrored
channelisenabled.Forexample,ifyouinstall64GBofmemoryusingRDIMMs,only32GBof
addressablememoryisavailablewhenyouusememorymirroredchannel.
ThefollowingdiagramliststheDIMMconnectorsoneachmemorychannel.
76Systemx3500M5InstallationandServiceGuide