model 59H Micro Channel

THEIBMTURBOWAYS155ATMADAPTER:OUTSTANDINGTHROUGHPUTANDPROCESSORUTILIZATIONDocumentNumberTR29.2157June1996AndrewRindosDavidCosbySteveWooletNetworkingHardwareDivisionResearchTrianglePark,NCiiAbstractInthispaper,wepresenttheverylatestperformancenumbers(throughputandworkstationprocessorutilization)fortheIBM1Turboways1155ATMadapter.Theanalysisincludestheperformanceofone,twoorthreeadapterssimultaneouslytransmittingdatabetweentwoRISCSystem/60001model59HMicroChannel1workstations,throughanIBM8260MultiprotocolHubwithaPRIZMA1ATMswitchswitch.DataisincludedfortwodifferentversionsoftheAIX1operatingsystem:4.1.4and4.2.TheprotocolexaminedwasTCP/IPusingtheindustrystandardbenchmarkapplication,Netperf.Asthedataindicates,withthedramaticimprovementsinworkstationprocessorutilizationprovidedbyAIX4.2,inconjunctionwithimprovementstoboththeTurboways155hardwareanddevicedriversoftware,aRISC/6000model59HworkstationisabletosupportthreeIBMTurboways155adapters,anddeliveranastonishingaggregate370Mbps(payload).WhenATMandSONEToverheadareaddedbackin,IBMadaptersaredeliveringmorethan426Mbpsatthemedialevel,or92%ofthecombinedcapacityofthreeOC3links.(Foroneortwosimultane-ouslytransmittingTurboways155adapters,thethroughputsareover96%ofthecapacityof,respectively,oneortwoOC3links.)Improvedprocessorutilizationalsotranslatestoimprovedsingleadapterthroughputonlesspowerfulworkstations.Thisisduetoasmallerpercentageoftheprocessorconsumedbythedevicedriverandprotocolsoftware,leavingmorecapacityavail-ablefordatatransmission.ThispaperthereforepresentsmeasurementsfordatatransfersbetweenRISC/6000models355and580.Finally,thispapercontainsdirectionsforreplicatingtheseresultsatcustomersitesand/oratindependenttestlabs.ThesemeasuredresultsclearlyplacetheIBMTurboways155attheforefrontofATMadaptersinperformance.TheyemphasizeIBM'sabilitytogloballyoptimizetheend-to-endnetworkperformanceofseveralproducts,madepossiblebythefactthatIBMoffersacompletesolution(includingworkstations,operatingsystems,adapters,switches,etc.).Thecustomercanexpectthissameexpertiseandcommit-menttohighqualityandperformance,demonstratedinthedesignofMicroChannel-basedadapters,tocarryovertoitsPCI-based(andotherbus)adapters,ATMswitchesandotherATMproducts.KEYWORDSATMNetworkingPerformanceClassicalIPAbstractiiiAbstractivContentsINTRODUCTION1PERFORMANCEMEASUREMENTS3MODEL59HMEASUREMENTS4MULTIPLEADAPTERPERFORMANCEMEASUREMENTS7MODEL355AND580MEASUREMENTS8THETRUEVALUEOFATURBOWAYSADAPTER10REFERENCES11NOTES11AppendixA.REPLICATINGTHESERESULTSWITHYOURCUSTOMERS12ContentsvContentsviACKNOWLEDGEMENTSTheauthorswouldliketoacknowledgetheassistanceofRichardJohnson,CarlGyllenhammer,BrianMutz,PaulQuackenbush,andKenWilsonofNHDinthiswork,aswellasDaisyChangandHermanDierksoftheAIXSystemsDivision.TheauthorswouldalsoliketoacknowledgetheassistanceofProfs.MladenVouk,IoannisViniotisandArneNilsson,aswellasPhilEmerandScottCallicut,ofNorthCarolinaStateUniversity.ACKNOWLEDGEMENTSviiACKNOWLEDGEMENTSviiiINTRODUCTIONIBMdevelopmentcontinuestomoveforwardwithimprovementstoitsproductline.ImprovementshavebeenmadetoboththeTurboways155ATMadapterhardwareanddevicedriversoftware,aswellastoAIX4.2,whichtogetherprovidedramaticallyimprovedworkstationprocessorutilizations.WhatthismeansisthattheAIXandATMdevicedriversconsumeamuchsmallerpercentageofthework-stationprocessorcapacityduringtheirexecution.Thisresultsinmoreprocessorcapacityavailablefortheexecutionofapplicationsandothersoftwarethatmustrunsimultaneouslyduringdatatransmission.Theendresultisdramaticallyhigherdatathroughputs.Thisabilitytoimproveseveralproductssimultaneouslytoyielddra-maticallyimprovedperformanceandgreaterfunctionalityisoneoftheadvantagesacustomerobtainswhenchoosinganIBMsolution.End-to-endperformanceisrarelyimprovedbylocalchangestoasingleproduct.OnlyIBMprovidessuchawiderangeofproductsforatotalsolution,whichinturnallowsittogloballyoptimizetheperformanceofanetwork.TheplotteddatainFigure1belowrepresentsmeasuredTCP/IPthroughputasafunctionoffilesizefortheTurboways155ATMadapter,usingtheindustrystandardbenchmarkNetperf.TheoperatingsystemwasthecurrentreleaseofAIX,version4.2.ThemeasureddatawastransmittedbetweentwoRISC/6000model59Hs,eachcontainingaMicroChannelTurboways155ATMadapter.(The59HrepresentsoneofthemostpowerfulRISC/6000workstationsofferedbyIBM.ItusesthePower2architecture,witha92intSPCmarkof122.4.)TheworkstationswereconnectedthroughaPRIZMAATMswitchwithinanIBM8260Multipro-tocolHub.Thethroughputpresentedbelowrepresentsadapter-levelthroughput,i.e.,theactualnumberofbitsperunittimethatmustbedeliveredbytheadaptertotheOC3media,whichincludesbothATMandSONEToverhead(see,e.g.,[1],[2]).Thebuffersize,etc.parametervaluesusedinthesestudiesarereportedinthesectionReplicatingTheseResultswithYourCustomers.Figure1.TCP/IPThroughputfortheTurboways155ATMAdapterINTRODUCTION1AsaresultofthesignificantimprovementsinefficiencywithAIX4.2andtheadapterhardware/software,anIBMRISC/6000model59Hwascapableofsup-portinguptothreeTurboways155ATMadapterssimultaneously.ThethreecurvesinFigure1thereforerepresentthethroughputsgeneratedbyo