Transcript Recap

Recap
(from Previous
Lecture)
1
Computer Architecture
• Computer Architecture involves 3 interrelated components
– Instruction set architecture (ISA): The actual
programmer-visible instruction set and serves as the
boundary between the software and hardware.
– Organization: includes the high-level aspects of a
computer’s design such as: The memory system, the
bus structure, and the internal CPU unit.
– Hardware: Refers to the specifics of the machine
such as detailed logic design and packaging technology.
2
Computer Architecture
Technology
Programming
Languages
Applications
Computer Architecture:
• Instruction Set Design
• Organization
• Hardware
Operating
Systems
History
Measurement &
Evaluation
Three Computing Markets Today
Desktop
Server
Embedded
4
Desktop Computer Systems
• For “General-Purpose” Use
– Word-Processing, Web surfing, Multimedia, etc.
– Computation and Programming
• What’s in the box
–
–
–
–
Microprocessor
Memory - DRAM
Hard disk(s), CDROM/DVD, etc.
I/O - mouse, keyboard, video card, monitor, network, etc.
• Important Issues:
–
–
–
–
Optimized for price-performance
Performance - how fast is “fast enough”?
Cost
Basic capabilities (and expandability)
5
Server Computer Systems
• Large-Scale Services
– File storage
– Computation (e.g., supercomputers)
– Transaction Processing, Web
• What’s in the Box(es)
– Microprocessor(s)
– Hard disks
– Network Interface(s)
• Important issues:
– Performance
– Reliability, availability
– Scalability
One Rack-Mount PC Unit
(Google uses ~ 10,000)
6
Embedded Computer Systems
• Computer as part of larger system
– Consumer electronics, appliances
– Networking, telecommunications
– Automotive / aircraft control
• What’s in the box
– Microcontroller / Microprocessor / System on Chip
(SOC)
– Memory: RAM, ROM; Disk
– Special-purpose I/O (including analog stuff)
• Important issues
– Cost, Power Consumption
– Performance (against real-time constraints)
– Reliability and Safety
7
Trends in Computer Architectures
•
Computer architectures has been advancing at
a very fast rate
•
These advances can be attributed to advances
in technology as well as advances in computer
design
– Advances in technology (e.g., microelectronics, VLSI,
packaging, etc) have been fairly steady
– Advances in computer design (e.g., ISA, Cache,
RAID, ILP, etc.) have a much bigger impact (This is
the theme of this class).
8
Trends in Technology
•
Trends in Technology followed closely Moore’s Law
“Transistor density of chips doubles every 1.5-2.0
years”
•
As a consequence of Moore’s Law:
•
–
Processor speed doubles every 1.5-2.0 years
–
DRAM size doubles every 1.5-2.0 years
–
Etc.
These constitute a target that the computer
industry aim for.
9
Growth in processor performance
Performance (vs. VAX-11/780)
10000
From Hennessy and Patterson, Computer
Architecture: A Quantitative Approach, 4th
edition, October, 2006
20%/year
1000
52%/year
100
10
25%/year
1
1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006
• VAX
: 25%/year 1978 to 1986
• RISC + x86: 52%/year 1986 to 2002
• RISC + x86: 20%/year 2002 to present
10
Integrated Circuits Capacity
11
Today: VLSI Microprocessors
Process Shrinks
Pentium® 4
42M transistors / 1.3-1.8GHz
49-55W
L=180nm
Pentium® 4 “Northwood” Pentium® 4 “Prescott”
55M transistors / 2-2.5GHz
55W
L=130nm Area=131mm2
125M transistors / 2.8-3.4GHz
115W
L=90nm Area=112mm2
12
Today: VLSI Microprocessors
Intel Itanium® 2
410M transistors / 1.3GHz / 130W
L=130nm Area=374mm2
Image source: Intel Corporation www.intel.com
Intel Core 2 Duo
291M transistors / 2.67GHz / 65W
L=65nm Area=143mm2
13
MOORE’s LAW
Processor-DRAM Memory Gap (latency)
100
10
1
µProc
60%/yr.
“Moore’s Law”
(2X/1.5yr)
Processor-Memory
Performance Gap:
(grows 50% / year)
DRAM
DRAM
9%/yr.
(2X/10 yrs)
CPU
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
Performance
1000
14
We need a balanced Computer
System
Computer System
CPU
Chain: As strong as its
[Clock Period,
CPI,
Instruction count]
Memory Bus
Weakest ring
[Bandwidth]
Memory
Secondary
Storage
[Capacity,
Cycle Time]
[Capacity,
Data Rate]
15