1. ISO 9126: Software Quality Internal Quality: Maintainability
Analyzability, Testability, Stability, Changeability
External Quality
Functionality
Usability
Reliability
Portability
Efficiency

3. Moore's Law
Noted that the number of transistors per unit area had doubled every year from 1958 to 1965
Expected the trend to last “for at least ten years”
Gordon Moore
Co-founder of Intel
Often misquoted as “the speed will double every 18 months”

5. Intel Processor Speeds over Time
10 GHz
1 GHz
100 MHz
10 MHz
1 MHz
Pentium 4
Pentium III
Pentium II
Pentium
80486
80386
80286
8086
8080
8008
4004

6. What’s the State-of-the-Art?
Fastest commercially available CPU: ~4GHz
Fastest experimental CPU: 500Ghz
Need to cool it down to 4°K, though
Fastest theoretical transistor: 1THz

7. The End of Moore’s Law? Production limitations Physical limitations
Bottleneck issues
Market issues

8. pre-1940s
Mechanical
1940s
Electromagnetic
Relays
1950s
Vacuum
Tubes
1960s
Transistors
since 1970s
Integrated
Circuits
The Future
Quantum Computers?

9. The Current Solution:
Parallelism

10. Process-Level Parallelism
Early computers (1950s and 1960s) could only run one program at a time
When it finished, it would run the next one
Multi-programming operating systems (1970s) made it appear as if multiple programs were running simultaneously 10

11. Instruction-Level Parallelism
Rather than wait for an instruction to finish, start the next one as soon as possible
Very common in RISC architectures
Pipelining: Fetch/decode one instruction while executing another 11

12. Thread-Level Parallelism
Modern programming languages support threads, which allow a program to do more than one thing at a time
Examples
Reading data from one source while writing to another
Performing two parts of a calculation simultaneously
Handling interaction with multiple users at the same time 12

13. Today Concurrency (threads) in C
Does concurrency really make your code faster?
Race conditions and synchronization
Short break; head to Moore 207
Lab assignment