1. Sogang University Advanced Computing System Chap 2. Processor Technology Hyuk-Jun Lee, PhD Dept. of Computer Science and Engineering Sogang University Seoul, Korea Email: hyukjunl@sogang.ac.kr

2. Sogang University Contents Single cycle processr Pipelined processor Deeply pipelined processor Wide or superscalar processor Out-of-order execution processor

3. Sogang University Why do we study different processor types?  Different processor architectures provide different performance and power consumption for given applications.  High performance processor with high clock frequency consumes more power than low performance processor for the same performance. Performance and power of big and little processor for web page loading [Zhu et al, HPCA ‘13]

4. Sogang University 4 Picture of processor  Area is translated into cost and performance  There is a trade-off between cost and performance

5. Sogang University 5 Single cycle processor design

6. Sogang University Pipelining Analogy Pipelined laundry: overlapping execution – Parallelism improves performance Four loads: Speedup = 8/3.5 = 2.3 Non-stop: Speedup = 2n/0.5n + 1.5 ≈ 4 = number of stages

7. Sogang University MIPS Pipeline Five stages, one step per stage 1.IF: Instruction fetch from memory 2.ID: Instruction decode & register read 3.EX: Execute operation or calculate address 4.MEM: Access memory operand 5.WB: Write result back to register

8. Sogang University 8 Pipelined processor design

9. Sogang University 9 Processor performance

10. Sogang University 10 5 stage pipelined processors

11. Sogang University 11 Improving the 5-stage pipeline performance

12. Sogang University 12 Deeper pipelines

13. Sogang University 13 Deeper pipeline review

14. Sogang University 14 Wide or superscalar pipelines

15. Sogang University 15 Superscalar pipelines review

16. Sogang University 16 Diversified pipelines

17. Sogang University 17 Modern superscalar out-of-order processor

18. Sogang University 18 Memory Hierarchy in Modern Processors

19. Sogang University 19 Challenges for Superscalar Processors