49-The Stanford DASH Multiprocessor.pdf

THESTANFORDDASHMULTIPROCESSORDANIELLENOSKI,JAMESLAUDON,KOUROSHGHARACHORLOO,WOLFDIETRICHWEBER,ANOOPGUPTA,JOHNHENNESSY,MARKHOROWITZ,ANDMONICASLAMSTANFORDUNIVERSITYDIRECTORYBASEDCACHECOHERENCEGIVESDASHTHEEASEOFUSEOFSHAREDMEMORYARCHITECTURESWHILEMAINTAININGTHESCALABILITYOFMESSAGEPASSINGMACHINESHECOMPUTERSYSTEMSLABORATORYATSTANFORDUNIVERSITYISDEVELOPINGASHAREDMEMORYMULTIPROCESSORCALLEDDASHANABBREVIATIONFORDIRECTORYARCHITECTUREFORSHAREDMEMORYTHEFUNDAMENTALPREMISEBEHINDTHEARCHITECTUREISTHATITISPOSSIBLETOBUILDASCALABLEHIGHPERFORMANCEMACHINEWITHASINGLEADDRESSSPACEANDCOHERENTCACHESTHEDASHARCHITECTUREISSCALABLEINTHATITACHIEVESLINEARORNEARLINEARPERFORMANCEGROWTHASTHENUMBEROFPROCESSORSINCREASESFROMAFEWTOAFEWTHOUSANDTHISPERFORMANCERESULTSFROMDISTRIBUTINGTHEMEMORYAMONGPROCESSINGNODESANDUSINGANETWORKWITHSCALABLEBANDWIDTHTOCONNECTTHENODESTHEARCHITECTUREALLOWSSHAREDDATATOBECACHED,THEREBYSIGNIFICANTLYREDUCINGTHELATENCYOFMEMORYACCESSESANDYIELDINGHIGHERPROCESSORUTILIZATIONANDHIGHEROVERALLPERFORMANCEADISTRI