1. CS 161 Design and Architecture of Computer Systems Lecture 1 Instructor: L.N. Bhuyan (http://www.cs.ucr.edu/~bhuyan) Adapted from notes by Dave Patterson (http://www.cs.berkeley.edu/~patterson)

2. Course Administration °Instructor:Laxmi N. Bhuyan (bhuyan@cs.ucr.edu) (http://www.ucr.edu/~bhuyan)bhuyan@cs.ucr.eduhttp://www.ucr.edu/~bhuyan Tel: (951)827-2244 351 Engg. 2 Office Hours: W 3-4.30 or by appt °TA: E-mail: rhalstea@cs.ucr.edu Office Hrs: EBU 2 Room 110

3. Course Administration °Text: Computer Organization and Design: The Hardware/Software Interface, Patterson and Hennessy, 4th Ed. ° Prerequisite: Assembly Language (CS061) and Digital system (CS120B) °Grade breakdown Test 1 (Chapters 1 and 2) 25% Test 2 (Chapter 4) 30% Test 3 (Chapters 5-7) 25% Homework Assignments 20% °Penalty for late homework °Grades based on curve

4. Historical Perspective °Decade of 70’s (Microprocessors) Programmable Controllers Single Chip Microprocessors Personal Computers °Decade of 80’s (RISC Architecture) Instruction Pipelining Fast Cache Memories Compiler Optimizations °Decade of 90’s (Instruction Level Parallelism) Superscalar Processors Aggressive Code Scheduling Low Cost Supercomputing Out of Order Execution KILLER MICROS

5. Performance Growth In Perspective °Doubling every 18 months since 1982 Cars travel at 11,000 mph; get 4000 miles/gal Air Travel LA-NY in 90 seconds (Mach 200) Wheat yield 20,000 bushels per acre °Doubling every 24 months since 1970 Cars travel at 200,000 mph; get 50,000 miles/gal Air Travel LA-NY in 6 seconds (Mach 3,000) Wheat yield 300,000 bushels per acre

6. Technology => dramatic change °Processor logic capacity: about 30% per year clock rate: about 20% per year °Memory DRAM capacity: about 60% per year (4x every 3 years) Memory speed: about 10% per year Cost per bit: improves about 25% per year °Disk capacity: about 60% per year

7. Technology => Dramatic Change °Processor 2X in performance every 1.5 years; 1000X performance in last decade °Main Memory DRAM capacity: 2x / 2 years; 1000X size in last decade Cost/bit: improves about 25% per year °Disk capacity: > 2X in size every 1.5 years Cost/bit: improves about 60% per year 120X size in last decade

8. Year 1000 10,000 100,000 1,000,000 10,000,000 100,000,000 1970197519801985199019952000 i80386 i4004 i8080 Pentium i80486 i80286 i8086 Trends: Microprocessor Capacity 2X transistors/Chip Every 1.5 years Called “Moore’s Law”: Alpha 21264: 15 million Pentium Pro: 5.5 million PowerPC 620: 6.9 million Alpha 21164: 9.3 million Sparc Ultra: 5.2 million Moore’s Law transistors

9. Trends: Memory Capacity (1 Chip DRAM) Year Bits 1,000 10,000 100,000 1,000,000 10,000,000 100,000,000 1,000,000,000 1970197519801985199019952000 year size(Megabit) 19800.0625 19830.25 19861 19894 199216 199664 2000256 Now 1.4X/yr, or doubling every 2 years °DRAM: Dynamic Random Access Memory where programs live while running; volatile (contrast with disk memory)

10. Trends: Processor Performance 0 100 200 300 400 500 600 700 800 900 8788899091929394959697 DEC Alpha 21264/600 Intel VC820 (Pentium III, 1.0 GHz) DEC Alpha 5/500 DEC Alpha 5/300 DEC Alpha 4/266 IBM POWER 100 DEC AXP/ 500 HP 9000/ 750 Sun -4/ 260 IBM RS/ 6000 MIPS M/ 120 MIPS M 2000 1.54x/year 1000 1100

11. Why Study Computer Architecture °Aren’t they fast enough already? Are they? Fast enough to do everything we will EVER want? -AI, protein sequencing, graphics Is speed the only goal? -Power: heat dissipation + battery life -Cost -Reliability -Etc. Answer #1: requirements are always changing Answer #2: technology playing field is always changing

12. Classes of Computers °High performance (supercomputers) Supercomputers – Cray T-90 Massively parallel computers – Cray T3E °Balanced cost/performance Workstations – SPARCstations Servers – SGI Origin, UltraSPARC High-end PCs – Pentium quads °Low cost/power Low-end PCs, laptops, PDAs – mobile Pentiums

13. What is *Computer Architecture* Computer Architecture = Instruction Set Architecture + Organization + Hardware + …

14. What is “Computer Architecture”? I/O systemProcessor Compiler Operating System (Unix; Windows 9x) Application (Netscape) Digital Design Circuit Design Instruction Set Architecture °Key Idea: levels of abstraction hide unnecessary implementation details helps us cope with enormous complexity of real systems Datapath & Control transistors, IC layout Memory Hardware Software Assembler CS 161

15. What is “Computer Architecture”? °Computer Architecture = Instruction Set Architecture (ISA) -the one “true” language of a machine -boundary between hardware and software -the hardware’s specification; defines “what” a machine does; + Machine Organization -the “guts” of the machine; “how” the hardware works; the implementation; must obey the ISA abstraction °We will explore both, and more!

16. Forces on Computer Architecture Computer Architecture Technology Programming Languages Operating Systems Compiler Applications

17. Forces Acting on Computer Architecture °R-a-p-i-d Improvement in Implementation Technology: IC: integrated circuit; invented 1959 SSI  MSI  LSI  VLSI: dramatic growth in number transistors/chip  ability to create more (and bigger) FUs per processor; bigger memory  more sophisticated applications, larger databases °Tomorrow’s Science Fiction: ubiquitous computing: computers embedded everywhere °New Languages: Java, C++...

18. Machine Organization: 5 classic components of any computer Personal Computer Processor (CPU) (active) Computer Control (“brain”) Datapath (“brawn”) Memory (passive) (where programs, & data live when running) Devices Input Output Keyboard, Mouse Display, Printer Disk (where programs, & data live when not running) The components of every computer, past and present, belong to one of these five categories

19. Machine Organization Perspective °Capabilities & performance characteristics of principal Functional Units (FUs) of the CPU °Ways in which these components are interconnected to realize the ISA °Information flows between components °How such information flow is controlled °Levels of Machine Description Register Transfer Level (RTL) Gate Level (Digital Design)

20. CS161: Course Content Computer Architecture and Engineering Instruction Set DesignComputer Organization InterfacesHardware Components Compiler/System ViewLogic Designer’s View ­“Building Architect”­“Construction Engineer”

21. von Neumann Computer °1944: The First Electronic Computer ENIAC at IAS, Princeton Univ. (18,000 vacuum tubes) °Stored-Program Concept – Storing programs as numbers – by John von Neumann – Eckert and Mauchly worked in engineering the concept. °Idea: A program is written as a sequence of instructions, represented by binary numbers. The instructions are stored in the memory just as data. They are read one by one, decoded and then executed by the CPU.

22. Execution Cycle Instruction Fetch Instruction Decode Operand Fetch Execute Result Store Next Instruction Obtain instruction from program storage Determine required actions and instruction size Locate and obtain operand data Compute result value or status Deposit results in storage for later use Determine successor instruction

23. The Instruction Set: a Critical Interface instruction set software hardware The actual programmer visible instruction set

24. Instruction-Set Processor Design °Architecture(ISA) programmer/compiler view “functional appearance to its immediate user/system programmer” Opcodes, addressing modes, architected registers, IEEE floating point °Implementation (µarchitecture) processor designer/view “logical structure or organization that performs the architecture” Pipelining, functional units, caches, physical registers °Realization(chip) chip/system designer view “physical structure that embodies the implementation” Gates, cells, transistors, wires

25. Relationship Between the Three Aspects °Processors having identical ISA may be very different in organization. e.g. NEC VR 5432 and NEC VR 4122 °Processors with identical ISA and nearly identical organization are still not nearly identical. e.g. Pentium II and Celeron are nearly identical but differ at clock rates and memory systems  Architecture covers all three aspects.