CPS 101 Introduction to
Computational Science
Wensheng Shen
Department of Computational Science
SUNY Brockport
Chapter 2 Computer hardware
and software
http://en.wikipedia.org/wiki/Computer_hardware
Computer hardware

Computer hardware is the physical part
of a computer, that includes motherboard,
CPU, memory, keyboard, monitor, etc.

PC (Personal Computer): A personal
computer is a computer whose price, size,
and capabilities make it useful for
individuals.
The parts inside a computer

Motherboard
CPU


A central
processing unit
(CPU)
Executing a program.
CPU Chip
Control unit
registers
ALU
bus interface
RAM (Random Access Memory)
-
-
-
More RAM will normally contribute to a
faster PC.
RAM is always removable as it sits in slots in
the motherboard
The RAM slots are normally located next to
the CPU socket.
Random-Access Memory
(RAM)


Static RAM (SRAM)

Retains value indefinitely, as long as it is kept powered.

Relatively insensitive to disturbances such as electrical noise.

Faster and more expensive than DRAM.
Dynamic RAM (DRAM)

Value must be refreshed every 10-100 ms.

Sensitive to disturbances.

Slower and cheaper than SRAM.
SRAM vs DRAM Summary
Tran.
per bit
Access
time
Persist? Sensitive?
Cost
Applications
SRAM
6
1X
Yes
No
100x
cache memories
DRAM
1
10X
No
Yes
1X
Main memories,
frame buffers
BUS

Transfers data
between components
inside a computer.
PCI
Peripheral Component
Interconnect
BIOS


A coded program
embedded on a chip.
Recognizes and controls
various devices that
make up the PC.
Hard Disk Drive (HDD)

A hard disk drive or
hard disk, is a nonvolatile storage device
which stores digitally
encoded data on rapidly
rotating platters with
magnetic surfaces
Video (graphic) card

A video card, or
graphics card, is an
expansion card that is
plugged into a slot on
the computer's
motherboard, whose
function is to generate
and output images to a
display.
Sound Card

Sound card


Speaker
For entertainment
purpose
Network card



Allow computers to communicate over
a computer network.
It provides physical access to a
networking through the use of MAC
addresses.
It allows users to connect to each
other either by using cables or
wirelessly.
IP Address






A name indicates what we seek.
An address indicates where it is.
A route indicates how to get there
An IP address is an identification assigned to devices participating
in a computer network utilizing the Internet Protocol.
IP addresses are stored as binary numbers, but are usually
displayed in human-readable notations, such as 208.77.188.166 (for
IPv4), and 2001:0db8:0000:0000:0000:0000:1428:57ab (for IPv6).
The original IP address is a 32-bit number system, now named
Internet Protocol Version 4 (IPv4), which is still in use today.
Due to the enormous growth of the Internet and the resulting
depletion of the address space, a new addressing system (IPv6),
using 128 bits for the address, was developed.
The IP address is globally unique.
The IP address is the logical address of a node in the network.
MAC Address



MAC address is a unique number to each IP
network adapter which is 48 bits long.
It is the physical address of each network
adapter.
The MAC address is commonly written as a
sequence of 12 hexadecimal digits as follows


48-3F-0A-91-00-BC
MAC addresses map to logical IP addresses
through the Address Resolution Protocol
(ARP)
How to find IP Address
Windows 95/98:
Go to Start/Run and do the command winipcfg
Windows 2000, XP, Vista:
Go to a command prompt and do ipconfig
On the Macintosh:
Apple Menu --> Control Panels --> TCP/IP Control Panel
On Mac OS X:
(1) Open system preferences
(2) Under internet and network, click 'network'
ROM
-
-
Data stored in ROM cannot
be modified
Every computer requires
some form of non-volatile
storage to store the initial
program.
Programmable read-only
memory (PROM)
Erasable programmable
read-only memory (EPROM)
Computer software

Computer software, consisting of programs,
enables a computer to perform specific tasks, as
opposed to its hardware which can only do the
tasks they are mechanically designed for. The
term includes application software such as
word processors which perform productive tasks
for users, system software such as operating
systems, which interface with hardware to run
the necessary services for user-interfaces and
applications, and middleware which controls
distributed systems.
Operating system


An operating system (OS) is the software
that manages the sharing of the resources of
a computer.
An operating system performs basic tasks
such as




controlling and allocating memory,
prioritizing system requests,
controlling input and output devices,
facilitating networking and managing file systems.
Modern operating systems


Unix-like operating systems: Unix is a
computer operating system originally
developed in 1969 by a group of AT&T
employees at Bell Labs, including Ken
Thompson, Dennis Ritchie and Douglas
McIlroy
Variants of Unix: HP-UX, Sun-Solaris,
IBM-AIX, and Linux.
Modern operating systems


Microsoft Windows: The Microsoft Windows
family of operating systems originated as a
graphical layer on top of the older MS-DOS
environment for the IBM PC. Modern versions
are based on the newer Windows NT core.
Windows runs on 32-bit and 64-bit Intel and
AMD processors
Windows family: Windows98, Windows2000,
WindowsXP, Vista
Modern operating systems

Mac OS X:



a graphical operating systems developed,
marketed, and sold by Apple Inc., running on all
Macintosh computers.
Mac OS X is the successor to the original Mac OS,
which had been Apple's primary operating system
since 1984.
Mac OS X is a Unix-like operating system
Market share of operating
systems on PCs in 2007
January
February
March
April
May
June
July
Windows
92.58%
93.05%
93.24%
92.85%
92.68%
92.93%
92.86%
Mac OS
6.22%
6.38%
6.08%
6.21%
6.46%
6.00%
5.97%
Linux
0.35%
0.42%
0.57%
0.80%
0.70%
0.71%
0.75%
Application software

Application software is a subclass of
computer software that employs the
capabilities of a computer directly to a task
that the user wishes to perform. This should
be contrasted with operating system which
is involved in integrating a computer's various
capabilities, but typically does not directly
apply them in the performance of tasks that
benefit the user.
Application software

Typical application software: word
processors, spreadsheets, media
players, games, education, etc.
The relation between
hardware and software



computer hardware are the physical interconnections
and devices required to store and execute (or run) the
software.
In computers, software is loaded into RAM and executed
in the CPU. At the lowest level, software consists of a
machine language specific to an individual processor.
A machine language consists of groups of binary values
specifying processor instructions (object code), which
change the state of the computer from its preceding
state.



Software is an ordered sequence of instructions for
changing the state of the computer hardware in a
particular sequence.
It is usually written in high-level programming
languages that are easier and more efficient for
humans to use (closer to natural language) than
machine language.
High-level languages are compiled or interpreted into
machine language object code..
Computer clock speed



Computer clock speed refers to the number of pulses per
second generated by an oscillator that sets the time for
the processor.
Clock speed is usually measured in MHz (megahertz, or
millions of cycles per second) or GHz (gigahertz, or
billions of cycles per second). Today's personal
computers run at a clock speed in the hundreds of
megahertz and some exceed one gigahertz. The clock
speed is determined by a quartz-crystal circuit.
Computer clock speed has been roughly doubling every
year. The Intel 8088, common in computers around the
year 1990, ran at 4.77 MHz. The 1 GHz mark was passed
in the year 2000.



Clock speed is one measure of the power of a computer, but
it is not always directly proportional to the performance level.
If you double the speed of the clock, leaving all other
hardware unchanged, you will not necessarily double the
processing speed. The type of microprocessor, the bus
architecture, and the nature of the instruction set all make a
difference. In some applications, the amount of random
access memory (RAM) is important, too.
Some processors execute only one instruction per clock cycle.
More advanced processors can perform more than one
instruction per clock pulse. The latter type of processor will
work faster at a given clock speed than the former type.
Similarly, a computer with a 32-bit bus will work faster at a
given clock speed than a computer with a 16-bit bus.
Another way of measure CPU speed is millions of instructions
per second (MIPS).
CPU Clock Rates
processor
clock rate(MHz)
cycle time(ns)
1980
8080
1
1,000
1985
286
6
166
1990
386
20
50
1995
Pent
150
6
2000
P-III
750
1.6
2000:1980
750
1/750
More concepts


Parallel computer
Supercomputer
Parallel Computer



Parallel computers consists of multiple
processors.
Distributed memory computer, shared
memory computer.
Cluster computing (Dr. Thomas
Sterling and Donald Becker).
Supercomputers



Supercomputers are the most powerful computers
in the world at the time when it is made, in terms of
the speed of calculation.
The term supercomputer itself is time dependent,
and today's supercomputer tends to become
tomorrow's normal computer.
Example: Cray X-MP/4, supercomputer 1983,
941 MFLOPS, used in Los Alamos National
Laboratory; Lawrence Livermore National
Laboratory; Battelle; Boeing
Why supercomputer


Supercomputers are used for highly calculation-intensive
tasks such as problems involving quantum mechanical
physics, weather forecasting, climate research
(including global warming), molecular modeling
(computing the structures and properties of chemical
compounds, biological macromolecules, polymers, and
crystals), physical simulations (such as simulation of
airplanes in wind tunnels, simulation of the
detonation of nuclear weapons, and research into
nuclear fusion), cryptanalysis, and the like.
Major universities, military agencies and scientific
research laboratories are heavy users.
Measuring the performance of
supercomputers


The speed of a supercomputer is generally
measured in FLOPS (FLoating Point
Operations Per Second), commonly used with
an SI prefix such as mega, giga, tera, or
peta. TFLOPS (teraflops) means 1012 FLOPS.
PFLOPS (petaflops) means 1015 FLOPS)
This measurement is based on a particular
benchmark which does LU decomposition of a
large matrix.
Architecture of modern
supercomputers




The top ten supercomputers on the
Top500 list have the same top-level
architecture: a cluster of MIMD
multiprocessors, each of them is SIMD.
MIMD+SIMD
MIMD: multi-instruction multi-data
SIMD: single-instruction multi-data



As of November 2006, the fastest machine is Blue
Gene/L. This machine is a cluster of 65,536 computers,
each with two processors, each of which processes two
data streams concurrently.
Blue Gene computers are designed to reach operating
speeds in the petaflops range, and currently reaching
sustained speeds over 360 teraflops.
It is a cooperative project among IBM (particularly the
Thomas J. Watson Research Center), the Lawrence
Livermore National Laboratory, the United States
Department of Energy (which is partially funding the
project), and academia. There are four Blue Gene
projects in development: BlueGene/L, BlueGene/C,
BlueGene/P, and BlueGene/Q