Hardware and Software Basics

Shirley Moore and Kay RoyCS 1401 Spring 2013January 24/28, 2013

Today’s Agenda

• Syllabus discussion (5 min)• Qualtrics survey results (3 min)• History of Computing recap (7 min)• Sharing of computer history timeline information

(15 min)• Computers and Computational Processes

lecture/discussion/demo (40 min)• Reflection (5 min)• Special guest (5 min)

Computational Process

• What is a computational process?• What is not a computational process?

– Calculating final grades for a class– Reading a book– Changing gears in an automatic transmission car– Learning to ride a bicycle– Solving a system of linear equations– Solving a math word problem– Playing chess

Restricted Over-simplified Definition

• A computational process takes input and manipulates it by executing a sequence of instructions to produce output.

Von Neumann Architecture

Note that both instructions and data are stored in memory.What of the above is true for today’s computers?What of the above is an over-simplification for today’s computers?

Execution of a Computational Process by a von Neumann Computer

1 Load program into memory2 Repeat until done (fetch-decode-execute cycle)

a. Fetch instruction into control unitb. Decode instructionc. Execute instruction (e.g., read value from memory,

arithmetic operation, write value to memory, read from input device, write to output device)

Do demo at http://ib-computing.net/html/FlashMovies/FE_cycle.htm

Learn the Lingo!

• Bits and Bytes– http://guides.macrumors.com/Bits_And_Bytes

• Computing Units– http://guides.macrumors.com/Computing_Units

• When kilo ≠1000– 1 kilobyte = 1024 bytes– Why?

Intel CPU Trends

Moore’s Law

Moore, Gordon E. (1965). "Cramming more components onto integrated circuits”, Electronics Magazine.

Dual-core Processor

Image from Wikipedia Commons http://en.wikipedia.org/wiki/File:Dual_Core_Generic.svg

Dual core: 2 x 3 GHz < 6 GHz

• Why?• When is a second core useful?• When does a second core NOT help?

Intel Sandy Bridge Processor

Image from The Register http://www.theregister.co.uk/2011/02/25/intel_westmere_ex_sandy_bridge_ep_xeons/page3.html

Sandy Bridge Core Microarchitecture

Image from http://www.techpowerup.com/forums/showthread.php?t=169087

Why Multicore?

• Advantages

• Disadvantages