PIPELINES Parallel Level 1PARALLEL STAGESPIPELINE PERFORMANCEPIPELINE SPEEDUPPIPELINE EFFICIENCYKennesaw State UniversityE X C E E D I N G E X P E C T A T I O N SPipelinesCSIS 4490 N-Tier Client/Server ArchitecturesDr. HogansonPIPELINES Parallel Level 1•Pipelines are an architectural enchancement that improves the performance of a computer system without increasing the clock speed•Pipelines take advantage of inherent parallelism in instructions•All instructions go through the same set of phases in the process of begin executed:–INSTRUCTION FETCH–INSTRUCTION DECODE–OPERAND FETCH–EXECUTION–RESULT STORE (not all architectures)Kennesaw State UniversityE X C E E D I N G E X P E C T A T I O N SPipelinesCSIS 4490 N-Tier Client/Server ArchitecturesDr. HogansonPARALLEL STAGES•Do each stage in parallel, with different instructions in each stage•Instructions flow from one stage to the nextStagestime IF DE OF EX RS DONE1 12 2 13 3 2 14 4 3 2 15 5 4 3 2 16 6 5 4 3 2 17 7 6 5 4 3 2etc.LoadTimeOne Inst per cycle after firstKennesaw State UniversityE X C E E D I N G E X P E C T A T I O N SPipelinesCSIS 4490 N-Tier Client/Server ArchitecturesDr. HogansonPIPELINE PERFORMANCE•k: stages in pipeline•t: time to do each stage (actually slowest stage)•n: number of instructions to be processedTime required for non-pipelined processor: = nktTime required for pipelined processor:1st instruction: kt (pipeline load)All after 1st (n-1 after 1st): (n-1)t= kt + (n-1)tKennesaw State UniversityE X C E E D I N G E X P E C T A T I O N SPipelinesCSIS 4490 N-Tier Client/Server ArchitecturesDr. HogansonPIPELINE SPEEDUPSPEEDUP is measured as SERIAL TIME divided by PARALLEL TIMEknnknknktnktnktMEPARALLELTISERIALTIME,n largefor Or,1)1(Kennesaw State UniversityE X C E E D I N G E X P E C T A T I O N SPipelinesCSIS 4490 N-Tier Client/Server ArchitecturesDr. HogansonPIPELINE EFFICIENCY•EFFICIENCY is measured as the ratio of SPEEDUP over NUMBER OR PROCESSING ELEMENTS (in this case stages)11nknknknkSTAGESSPEEDUPEFFICIENCYEx: 100 instructions, 4 stages,