Module 1: Introduction Topic 2: Trends & Challenges

1. Module 1: IntroductionTopic 2: Trends & Challenges OGI EE564 Howard Heck Section 1.2

2. Where Are We? • Introduction • Overview • Trends & Challenges • Interconnect Technology • Transmission Line Basics • Analysis Tools • Metrics & Methodology • Advanced Transmission Lines • Multi-Gb/s Signaling • Special Topics Section 1.2

3. Contents • Moore’s Law & Its’ Impact On Interconnect Design • System Architecture Evolution • Bus Scaling • System Bus • Cache Bus • Memory Bus • I/O Buses • Cost Constraints • Summary • References • Appendix: Scaling Trends Section 1.2

4. Moore’s Law • Moore’s Law: Silicon integration doubles every 2 years. • Application to microprocessors: Processor performance doubles every two years. • How is the performance growth achieved? • Frequency scaling: smaller, faster devices • Increased parallelism (e.g. pipelines, superscalar): more devices • Increased function (e.g. floating point, MMX): more devices • So What? Moore’s law impacts interconnect. • Higher frequency processors demand more data to keep functional units occupied doing useful work. • This means more wires operating at higher frequency. Section 1.2

5. CPU Performance Trend (Frequency) Historically, 1 megabyte/second of data is supplied for each CPU MHz. Section 1.2

6. PC Architecture & Performance Evolution 486DX2 Processor (~1992) • 3 major buses • 33 MHz max frequency • 4 byte bus width Pentium® 4 Processor (2003) • 4 major buses • 66 - 800 MHz • 4-16 byte widths Section 1.2

7. PC Architecture & Performance Evolution Core® 2 Processor (2008) Section 1.2

8. Bus Performance Trends System Bus System Bus Frequency 10000 8080 8085 8086 8088 1000 80186 80286 80386 486DX 100 Frequency [MHz] 486DX2 486DX4 Pentium® Pentium® Pro Pentium® II 10 Celeron® Pentium® III Pentium® 4 Pentium® 4EE 1 1970 1975 1980 1985 1990 1995 2000 2005 2010 Year The CPU bus follows Moore’s Law, too. Section 1.2

9. Bus Performance Trends Memory • SOA (2008): • 1600 MHz • 25,600 MB/s Section 1.2

10. Cost Constraints Motherboard& Connectors(< 5% of total) O/S Fax/Modem CDROM Case Sound + Memory Speakers Hard Disk CPU Monitor + Video Card Power Supply Motherboard Components Approximate Cost Breakdown of a Desktop PC • Interconnect makes up <5% of the system cost. • Most technical problems can be solved with $. • High volume PC market can’t afford extra cost. The trend is toward even lower costs. • Designing Multi-GHz interconnects to fit in sub $1000 PCs is a huge challenge. Section 1.2

11. Summary • Moore’s law predicts the rate of growth of microprocessor performance. This growth drives increased interconnect performance requirements. • Interconnect designers are confronted with the challenges (opportunities) created by the demand for performance and the cost constraints of commodity computing. • Sales volume of PC system drops off sharply when the price exceeds the volume desktop price barrier. • System performance and function increase over time while selling price is decreasing. • Interconnect components account for < 5% of system cost. • Interconnect engineers must satisfy increased performance demands without increasing the cost of the solution. Section 1.2

12. References The data contained in the graphs was gathered from numerous sources, including: 8086/80286/80386/80486 • Component Data Catalog, Intel Corporation, 1980. • Microprocessors, Volume 1, Intel Corporation, 1992. • Intel486TM Microprocessors and Related Products, Intel Corporation, 1995. Pentium Processor • PentiumTM Processors and Related Products, Intel Corporation, 1995. • Pentium Processor, Intel Corporation, June 1997, Order Number 241997-010, http://developer.intel.com/design/pentium/datashts/241991.htm. • Pentium Processor with MMXTM Technology, Intel Corporation, June 1997, Order Number 243185-005, http://download.intel.com/design/MMX/datashts/24318504.pdf. • Pentium Processor Performance Brief, Intel Corporation, June 1997, Order Number 241557-010, http://download.intel.com/design/pentium/perfbref/24155710.pdf. Section 1.2

13. References #2 Pentium Pro Processor • Pentium Pro Processor Performance Brief, Intel Corporation, June 1997, Order Number 242768-006. Pentium II Processor • Pentium II Processor at 333 MHz, 300 MHz, 266 MHz, and 233 MHz, Intel Corporation, January 1998, Order Number 243335-003, http://developer.intel.com/PentiumII/datashts/243335.htm. • Pentium II Processor at 350 MHz, 400 MHz, and 450 MHz, Intel Corporation, August 1998, Order Number 243657-003, http://developer.intel.com/PentiumII/datashts/243657.htm. • Pentium II Processor Performance Brief, Intel Corporation, August 1998, Order Number 243336-006, http://developer.intel.com/procs/perf/doc/pii_august.htm. • Pentium II Processor Developer’s Manual, Intel Corporation, October 1997, Order Number 243502-001, ftp://download.intel.com/design/PentiumII/manuals/24350201.pdf. Section 1.2

14. References #3 Intel CeleronTM Processor • Intel Celeron Processor at 266 MHz, 300 MHz, 300A MHz, and 333 MHz, Intel Corporation, November 1998, Order Number 2436558-004, http://developer.intel.com/design/celeron/datashts/243658.htm. • Intel Celeron Processor Performance Brief, Intel Corporation, August 1998, Order Number 243706-003, http://developer.intel.com/procs/perf/doc/celeron_august.htm. System Technologies • Data regarding memory bandwidth metrics was provided by George Vergis of Intel Corporation. • Meeting System Demands with Synchronous DRAM Technology, Texas Instruments, http://www.ti.com/sc/docs/memory/brief.html. • Memory Latency Comparison, Rambus Inc., 1996. • Rambus Memory: Multi-Gigabytes/Second and Minimum System Cost, Rambus, Inc., 1997. • Synchronous DRAMs: The DRAM of the Future, IBM Microelectronics Division, 1997. Section 1.2

15. Appendix: PC Architecture Evolution Section 1.2

16. PC Architecture: 80486 Generation (~1992) • 3 major buses • 33 MHz maximum frequency Section 1.2

17. PC Architecture: Pentium® (~1996) • 3 major buses • 66 MHz maximum frequency • 64 bit bus width Section 1.2

18. PC Architecture: Pentium® II (~1997) • 5 major buses • 133/150 MHz • 64 bits Section 1.2

19. PC Architecture: Pentium® II (~1998) • 5 major buses • 100/133/225 MHz • 64 bits Section 1.2

20. PC Architecture: Pentium® III (~1999-2000) • 4 major buses • 133/266/800 MHz • 16-64 bits Section 1.2

21. PC Architecture: Pentium® 4 (2000) • 4 major buses • 133/266/800 MHz • 32-64 bits Section 1.2

22. PC Architecture: Pentium® 4 (2002) • 4 major buses • 133/266/800 MHz • 32-64 bits Section 1.2