Intel® 64 and IA-32 Architectures Optimization Reference Manual

USING PERFORMANCE MONITORING EVENTSMetricBus UtilizationReads from theProcessorWrites from theProcessorTable B-5. Performance Metrics - Bus (Contd.)Description% of time that bus isactually occupiedNumber of all read(includes RFOs)transactions on thebus that wereallocated in IO Queuefrom this processor(includes prefetches)Beware of granularityissues with this event.Also Beware ofdifferent recipes inmask bits for Pentium4 and Intel Xeonprocessors betweenCPUID model fieldvalue of 2 and modelvalue less than 2.Number of all writetransactions on thebus allocated in IOQueue from thisprocessor (excludesRFOs)Beware of granularityissues with this event.Also Beware ofdifferent recipes inmask bits for Pentium4 and Intel Xeonprocessors betweenCPUID model fieldvalue of 2 and modelvalue less than 2.Event Name or MetricExpression(FSB Data Ready)*Bus_ratio*100/ Non-Sleep Clock TicksIOQ_allocationIOQ_allocationEvent Mask ValueRequired1a. ReqA0, ALL_READ,OWN, PREFETCH(CPUID model < 2);1b. ReqA0, ALL_READ,MEM_WB, MEM_WT,MEM_WP, MEM_WC,MEM_UC,OWN, PREFETCH(CPUID model >= 2);2: Enable edgefiltering 1 in theCCCR.1a. ReqA0, ALL_WRITE,OWN(CPUID model < 2);1b. ReqA0, ALL_WRITE,MEM_WB, MEM_WT,MEM_WP, MEM_WC,MEM_UC, OWN(CPUID model >= 2).2: Enable edgefiltering 1 in theCCCR.B-18