x4=x4organization(4DQlinesperSDRAM)
x8=x8organization
x16=x16organization
–vistheSDRAMandsupportcomponentsupplyvoltage(VDD)
•Blank=1.2Vspecified
–wwwwwistheDIMMbandwidth,inMBps
12800=12.80GBps(DDR4-1600SDRAMs,8-byteprimarydatabus)
14900=14.93GBps(DDR4-1866SDRAMs,8-byteprimarydatabus)
17000=17.00GBps(DDR4-2133SDRAMs,8-byteprimarydatabus)
–mistheDIMMtype
L=LoadReductionDIMM(LRDIMM)
R=RegisteredDIMM(RDIMM)
–aaistheCASlatency,inclocksatmaximumoperatingfrequency
–bbistheJEDECSPDRevisionEncodingandAdditionslevel
–ccisthereferencedesignfileforthedesignoftheDIMM
–distherevisionnumberofthereferencedesignoftheDIMM
Note:TodeterminethetypeofaDIMM,seethelabelontheDIMM.Theinformationonthelabelisin
theformatxxxxxnRxxxPC3v-xxxxxx-xx-xx-xxx.Thenumeralinthesixthnumericalpositionindicates
whethertheDIMMissingle-rank(n=1),dual-rank(n=2),orquad-rank(n=4).
•ThefollowingrulesapplytoDDR4RDIMMspeedasitrelatestothenumberofRDIMMsinachannel:
–Whenyouinstall1RDIMMperchannel,thememoryrunsat2133MHz
–Whenyouinstall2RDIMMsperchannel,thememoryrunsat2133MHz
–Whenyouinstall3RDIMMsperchannel,thememorymayrunat1600or1866MHz,depending
onthememorysize.
–Allchannelsinaserverrunatthefastestcommonfrequency
–Donotinstallregistered,unbuffered,andloadreductionDIMMsinthesameserver
•Themaximummemoryspeedisdeterminedbythecombinationofthemicroprocessor,DIMMspeed,
DIMMtype,OperatingModesinUEFIsettings,andthenumberofDIMMsinstalledineachchannel.
•Intwo-DIMM-per-channelconfiguration,theserverautomaticallyoperateswithamaximummemory
speedofupto1600MHzwhenthefollowingconditionismet:
–Two1.35Vsingle-rank,dual-rank,orquad-rankRDIMMsorLRDIMMsareinstalledinthesame
channel.IntheSetuputility,MemoryspeedissettoMaxperformanceandLV-DIMMpowerissetto
Enhanceperformancemode.The1.35VRDIMMsorLRDIMMswillfunctionat1.5V.
•Theserversupportsamaximumof24single-rank,dual-rankRDIMMsor24quad-rankLRDIMMs.
•Thefollowingtableshowsanexampleofthemaximumamountofmemorythatyoucaninstallusing
rankedDIMMsorload-reducedDIMMs:
Table25.Maximummemoryinstallation
NumberofDIMMsDIMMtypeSizeTotalmemory
24
Single-rankRDIMM4GB96GB
24Dual-rankRDIMM
8GB192GB
24Dual-rankRDIMM
16GB384GB
Chapter5.Removingandreplacingcomponents161