Microprocessor

MICROPROCESSOR CENTRAL PROCESSING UNIT

What is a CPU? CPU stands for Central Processing Unit. Let us briefly study that name: •It is a processor, because it processes (moves and calculates) data. •It is central, because it is the center of PC data processing. •It is a unit, because it is a chip, which contains millions of transistors.

MANUFACTURERS

IBM CYRIX INTEL CORPORATION ADVANCED MICRO DEVICES(AMD)

BUS a series of connections that carry common signals

a typical processor has two important buses for carrying data and memory--addressing information

data bus address bus

- data bus the bundle of wires (or pins) used to send and receive data

The more signals that can be sent at the same time, the more data can be transmitted in a specified interval and, therefore, the faster the bus.

Internal Registers internal data bus

The size of the internal register is a good indication of how much information the processor can operate on at one time. 386 to the Pentium--use 32-bit internal registers 8088, 386SX, 386SL – use internal registers twice the width external data bus

HYBRID DESIGNS

80386 386SX 386DX

32-bit IR 16-bit data bus 32-bit IR 32-bit data bus

Pentium Twin data pipelines

32-bit IR

64-bit data bus

Address Bus the set of wires that carry the addressing information used to describe the memory location to which the data is being sent, or from which the data is being retrieved. The size (or width) of the address bus indicates the maximum amount of RAM that a chip can address.

The size of the data bus is an indication of the information-moving capability of the chip, and the size of the address bus tells you how much memory the chip can handle.

Intel Processor Memory-Addressing Capabilities Processor Family

Address Bus

Bytes

Kilobytes

Mbyte s

Gbytes

8088/8086

20-bit

1,048,576

1,024

1

none

286/386SX

24-bit

16,777,216

16,384

16

none

386DXPentium Pro

32-bit

4,294,967,296

4,194,304

4,096

4

Pentium II

36-bit

68,719,476,736

67,108,864 65,536

64

Processor Speed 1 hertz = one cycle per second The hertz was named for the German physicist Heinrich Rudolph Hertz. In 1885, Hertz confirmed through experimentation the electromagnetic theory, which states that light is a form of electromagnetic radiation and is propagated as wave

A single cycle is the smallest element of time for the processor. Every action requires at least one cycle and usually multiple cycles. To transfer data to and from memory, for example, an 8086 chip needs four cycles plus wait states.

A wait state is a clock tick in which Nothing happens to ensure that the processor isn't getting ahead of the rest of the computer

A 286 needs only two cycles plus any wait states for the same transfer.

MICROPROCESSOR

AVERAGE CYCLES PER INSTRUCTION

8086 and 8088

12

286 and 386

4.5

486

2

Pentium

1

100MHz Pentium is about equal to 200MHz 486 400MHz 386 or 286 1,000MHz 8088

Table 6.4  Intel Processor and Motherboard Speeds CPU Type/Speed

CPU Clock

Motherboard Speed

Pentium 60

1x

60

Pentium 66

1x

66

Pentium 75

1.5x

50

Pentium 90

1.5x

60

Pentium 100

1.5x

66

Pentium 120

2x

60

Pentium 133

2x

66

Pentium 150

2.5x

60

Pentium/Pentium Pro/MMX 166

2.5x

66

Pentium/Pentium Pro 180

3x

60

Pentium/Pentium Pro/MMX 200

3x

66

Pentium-MMX/Pentium II 233

3.5x

66

Pentium II 266

4x

66

Pentium II 300

4.5x

66

overclocking Most of the processors running at 50MHz and higher should have a heat sink installed to prevent the processor from overheating

Microprocessor Progression: Intel The following table helps you to understand the differences between the different processors that Intel has introduced over the years.

Name

Date

Transistors

Microns

Clock speed

Data width

MIPS

8080

1974

6,000

6

2 MHz

8 bits

0.64

8088

1979

29,000

3

5 MHz

16 bits 8-bit bus

0.33

80286

1982

134,000

1.5

6 MHz

16 bits

1

80386

1985

275,000

1.5

16 MHz

32 bits

5

80486

1989

1,200,000

1

25 MHz

32 bits

20

Pentium

1993

3,100,000

0.8

60 MHz

32 bits 64-bit bus

100

Pentium II

1997

7,500,000

0.35

233 MHz

32 bits 64-bit bus

~300

Pentium III

1999

9,500,000

0.25

450 MHz

32 bits 64-bit bus

~510

Pentium 4

2000

42,000,000

0.18

1.5 GHz

32 bits 64-bit bus

~1,700

Pentium 4 "Prescott"

2004

125,000,000

0.09

3.6 GHz

32 bits 64-bit bus

~7,000

Transistors is the number of transistors on the chip. You can see that the number of transistors on a single chip has risen steadily over the years. Microns is the width, in microns, of the smallest wire on the chip. For comparison, a human hair is 100 microns thick. As the feature size on the chip goes down, the number of transistors rises. Clock speed is the maximum rate that the chip can be clocked at. Clock speed will make more sense in the next section. Data Width is the width of the ALU. An 8-bit ALU can add/subtract/multiply/etc. two 8-bit numbers, while a 32-bit ALU can manipulate 32-bit numbers. An 8-bit ALU would have to execute four instructions to add two 32-bit numbers, while a 32-bit ALU can do it in one instruction. In many cases, the external data bus is the same width as the ALU, but not always. The 8088 had a 16-bit ALU and an 8-bit bus, while the modern Pentiums fetch data 64 bits at a time for their 32-bit ALUs. MIPS stands for "millions of instructions per second" and is a rough measure of the performance of a CPU. Modern CPUs can do so many different things that MIPS ratings lose a lot of their meaning, but you can get a general sense of the relative power of the CPUs from this column.

Microprocessor History A microprocessor -- also known as a CPU or central processing unit -- is a complete computation engine that is fabricated on a single chip. The first microprocessor was the Intel 4004, introduced in 1971. The 4004 was not very powerful -- all it could do was add and subtract, and it could only do that 4 bits at a time. But it was amazing that everything was on one chip. Prior to the 4004, engineers built computers either from collections of chips or from discrete components (transistors wired one at a time). The 4004 powered one of the first portable electronic calculators.

The first microprocessor to make it into a home computer was the Intel 8080, a complete 8-bit computer on one chip, introduced in 1974. The first microprocessor to make a real splash in the market was the Intel 8088, introduced in 1979 and incorporated into the IBM PC (which first appeared around 1982). If you are familiar with the PC market and its history, you know that the PC market moved from the 8088 to the 80286 to the 80386 to the 80486 to the Pentium to the Pentium II to the Pentium III to the Pentium 4. All of these microprocessors are made by Intel and all of them are improvements on the basic design of the 8088. The Pentium 4 can execute any piece of code that ran on the original 8088, but it does it about 5,000 times faster!

8088 (1978) - operates at 4.77Mhz (about 4,770,000 ticks or heartbeats per second - 8 bit data bus - used on IBM PCs and XTs (Extended Technology) 640K conventional memory barrier -Total of 1,024K (1mb) addressable location -Upper portion reserved for adapter and system BIOS -Lower portion (640k for DOS and applications) 8086 (1976) - 16 bit data bus - costly

Intel 8088 and 8086 Microprocessor

Intel 80186 and 80188 Microprocessor - increased instruction sets - 80186 (full 16 bit) - 80188 (8 bit) - Both combined on a single chip 15 to 20 of the 8086-8088 series system components (reduced number of components in computer design) - used for highly intelligent peripheral adapter cards, such as network adapters

Intel 80286 Microprocessor

80286 processor - abbreviated as 286 - introduced in 1981 - the CPU behind the IBM AT (Advance Technology) - 6Mhz (five times faster than a PC running at 4.77Mhz

Two modes of Operation Real-mode - acts essentially the same as an 8086 chip and is fully object-code compatible with the 8086 and 8088 Protected Mode - believed to have access to 1G of memory (including virtual memory) -16Mb of actual addressable memory - it cannot switch from protected mode to real mode without a hardware reset (a warm reboot) - Intel's first attempt to produce a CPU chip that supported multitasking (Windows)

Intel 80386 Microprocessor - introduced in 1985 - offers greater performance in almost all areas of operation - a full 32-bit processor - 386 can execute the real-mode instructions of an 8086 or 8088, but in fewer clock cycles - additional software capability (modes) and a greatly enhanced Memory Management Unit (MMU). - 386 can switch to and from protected mode under software control without a system reset Virtual real mode (sometimes called virtual 86 mode) - can run with hardware memory protection while simulating an 8086's real-mode operation

386DX Processors - full 32-bit processor - 32-bit internal registers - 32-bit internal data bus - 32-bit external data bus - 275,000 transistors in a VLSI (Very Large Scale Integration) - 132-pin package - less power requirement than 8086 - speed ranges form 16MHz to 33MHz; other manufacturers, primarily AMD and Cyrix, offered comparable versions with speeds up to 40MHz - The 386DX can address 4G of physical memory

386SX Processors - code named P9 chip - 386 capability at the cost of 286 - 16-bit system - can address only up to 16M of memory - speeds at 16 to 33 Mhz - signaled the end of 286 processors - 16MHz 386SX is not markedly faster than a 16MHz 286, but it does offer improved memory-management capabilities

386SL Processors - low-power CPU - same capabilities as the 386SX - designed for laptop systems in which low power consumption is needed - offer special power-management features (sleep modes) - chip includes an extended architecture that includes a System Management Interrupt (SMI) - the higher transistor count in the SL chips (855,000) compared with even the 386DX processor (275,000 -runs at 25MHz clock speed

Intel 80486 Microprocessor Four main features make a given 486 processor roughly twice as fast as an equivalent MHz 386 chip. These features are: -

Reduced instruction-execution time

Instructions in the 486 take an average of only two clock cycles to complete, compared with an average of more than four cycles on the 386.

80486 - Internal (Level 1) cache The built-in cache has a hit ratio of 90 to 95 percent, which describes how often zero-wait-state read operations will occur. External caches can improve this ratio further. - Burst-mode memory cycles A standard 32-bit (4-byte) memory transfer takes two clock cycles. After a standard 32-bit transfer, more data up to the next 12 bytes (or three transfers) can be transferred with only one cycle used for each 32-bit (4-byte) transfer. Thus, up to 16 bytes of contiguous, sequential memory data can be transferred in as little as five cycles instead of eight cycles or more. This effect can be even greater when the transfers are only 8 bits or 16 bits each

80486 - Built-in (synchronous) enhanced math coprocessor (some versions) (FPU – Floating-point unit) The math co- processor runs synchronously with the main processor and executes math instructions in fewer cycles than previous designs did. On average, the math coprocessor built into the DX-series chips provides two to three times greater math performance than an external 387 chip.

486 Processors - about twice as fast as the 386 - easily be upgraded to a DX2 or DX4 processor - the 486 rapidly killed off the 386 - spawned the widespread acceptance of GUIs - speeds from 16MHz all the way up to 120MHz

Intel DX2 and DX4 Operating Speeds versus Motherboard Clock Speeds Motherboard Clock Speed

16MHz

20MHz

25MHz

33MHz

40MHz

50MHz

DX2 processor speed

32MHz

40MHz

50MHz

66MHz

80MHz

N/A

DX4 (2x mode) speed

32MHz

40MHz

50MHz

66MHz

80MHz

100MHz

DX4 (2.5x mode) speed

40MHz

50MHz

63MHz

83MHz

100MHz

N/A

DX4 (3x mode) speed

48MHz

60MHz

75MHz

100MHz

120MHz

N/A

486DX Processors - introduced on April 10, 1989 - Two main features - Integration (math coprocessor,cache controller, cache memory) - Upgradability (double-speed OverDrive) -

32-bit internal register size 32-bit external data bus 32-bit address bus contains 1.2 million transistors on a piece of silicon no larger than a thumbnail - FPU is 100 percent compatible with 80387 co-processor

486SL Processors - SL Enhancement refers to a special design that incorporates special power-saving features - designed to be installed in laptop or notebook systems - eventually found their way into desktop systems - incorporates System Management Mode (SMM) - suspend/resume - designed to consume almost no power in the suspend state

486SX Processors - introduced in April 1991 - lower-cost version of the 486 - full DX processor, but the chip does not incorporate the FPU - had a completely different pinout - twice as fast as a 386DX with the same clock speed - normally available in 16, 20, 25, and 33MHz-rated speeds - SX/2 version up to 50 or 66MHz

487SX ( Math co-processor) & Overdrive processors

CPU

FPU

8086

8087

80286

80287

80386

80387

80486DX

Built in

80486SX

None

Pentium and thereafter

Built in

487 SX - a complete 25MHz 486DX CPU with an extra pin added and some other pins rearranged - provides math coprocessor functionality in the system - prepared its real surprise: the OverDrive processor - any system that supports the 487SX also supports the DX2/OverDrive chips

DX2/OverDrive and DX4 Processors

DX2/OverDrive and DX4 Processors - March 3, 1992, Intel introduced the DX2 speed-doubling processors - On May 26, 1992, DX2 processors were available in a retail version called OverDrive - Originally, the OverDrive versions of the DX2 were available only in 169-pin versions, which meant that they could be used only with 486SX systems that had sockets configured to support the rearranged pin configuration - On September 14, 1992, Intel introduced 168-pin OverDrive versions for upgrading 486DX systems. - DX2/OverDrive processors run internally at twice the clock rate of the host system - DX2 chip that doesn't run at double speed is the bus interface unit

Vacancy

Table 6.6  Intel 486/Pentium CPU Socket Types and Specifications Socket Number

No. of Pins

Pin Layout

Voltage

Supported Processors

Socket 1

169

17x17 PGA

5v

SX/SX2, DX/DX2*, DX4 OverDrive

Socket 2

238

19x19 PGA

5v

SX/SX2, DX/DX2*, DX4 OverDrive, 486 Pentium OverDrive

Socket 3

237

19x19 PGA

5v/3.3v

SX/SX2, DX/DX2, DX4, 486 Pentium OverDrive

Socket 4

273

21x21 PGA

5v

Pentium 60/66, Pentium 60/66

OverDrive Socket 5

320

37x37 SPGA

3.3v

Pentium 75-133, Pentium 75+ OverDrive

Socket 6

235

19x19 PGA

3.3v

DX4, 486 Pentium OverDrive

Socket 7

321

37x37 SPGA

VRM

Pentium 75-200, Pentium 75+ OverDrive

Socket 8

387

dual-pattern SPGA

VRM

Pentium Pro

Processor Designation

Replaces

Socket

Heat Sink

486 Pentium OverDrive

486SX/DX/SX2/DX 2

Socket 2 or 3

Active

60/66 Pentium OverDrive

Pentium 60/66

Socket 4

Active

Pentium OverDrive with MMX

Pentium 75/90/100

Socket 5/7

Active

OverDrive Compatibility Problems Although you can upgrade many older 486SX or 486DX systems with the OverDrive processors, some exceptions exist. Four factors can make an OverDrive upgrade difficult or impossible: - BIOS routines that use CPU-dependent timing loops - Lack of clearance for the OverDrive heat sink (25MHz and faster) - Inadequate system cooling - A 486 CPU that is soldered in rather than socketed

Pentium

®

- October 19, 1992, Intel announced P5 (Pentium) processor - shipped on March 22, 1993 - features twin data pipelines (superscalar technology ) u-pipe (primary pipe)- execute all integer and floating-point instructions v-pipe (secondary pipe) - execute only simple integer instructions and certain floating-point instructions pairing - operating on two instructions simultaneously in the different pipes - one of the first CISC (Complex Instruction Set Computer) chips - Branch Target Buffer (BTB) that employs a technique called branch prediction - SL enhanced (incorporate the SMM) - Built-in FPU - Tape Carrier Packaging

Pentium Processor Specifications Introduced:

March 22, 1993 (first generation); March 7, 1994 (second generation)

Maximum rated speeds:

60, 66MHz (first generation); 75, 90, 100, 120, 133, 150, 166, 200MHz (second generation)

CPU clock multiplier:

1x (first generation), 1.5x-3x (second generation)

Register size:

32-bit

External data bus:

64-bit

Memory address bus:

32-bit

Maximum memory:

4G

Integral-cache size:

8K code, 8K data

Integral-cache type:

Two-Way Set Associative, Write-Back Data

Burst-mode transfers:

Yes

Number of transistors:

3.1 million

Circuit size:

0.8 micron (60/66MHz), 0.6 micron (75-100MHz), 0.35 micron (120MHz and up)

External package:

273-pin PGA, 296-pin SPGA, Tape Carrier

Math coprocessor:

Built-in FPU (Floating-Point Unit)

Power management:

SMM (System Management Mode), enhanced in second generation

Operating voltage:

5v (first generation), 3.465v, 3.3v, 3.1v, 2.9v (second generation)

Generations of Pentium

First Generation Pentium -

60 and 66MHz processor speeds 273-pin PGA form factor and ran on 5v power ran at the same speed as the motherboard(1x clock) 0.8-micron BiCMOS process 3.1 million transistor count

Second Generation Pentium - March 7, 1994 - 75, 90 and 100MHz versions - Eventually, 120, 133, 150, 166, and 200MHz versions were also introduced - 0.6-micron (75/90/100MHz) BiCMOS technology - 120 and higher MHz second-generation versions incorporate an even smaller die built on a 0.35-micron - run on 3.3v power

Second Generation Pentium - come in a 296-pin SPGA (Staggered Pin Grid Array) - physically incompatible with the first-generation versions - 3.3 million transistors for additional clock-control SL enhancements on-chip Advanced Programmable Interrupt Controller dual-processor interface (Symmetric Multi-Processing ) - use clock-multiplier circuitry - single chip OverDrive upgrade

CPU Type/Speed

CPU Clock

Memory Bus Speed

Pentium 75

1.5x

50

Pentium 90

1.5x

60

Pentium 100

1.5x

66

Pentium 120

2x

60

Pentium 133

2x

66

Pentium 150

2.5x

60

Pentium 166

2.5x

66

Pentium 200

3x

66

Pentium-MMX Processor (Third Generation Pentium)

Third Generation Pentium (MMX) - code-named P55C -

released in January 1997 incorporates what Intel calls MMX technology clock rates of 66/166MHz, 66/200MHz, and 66/233MHz include superscalar architecture, multi-processor support, on-chip local APIC controller, and power management features - New features include a pipelined MMX unit, 16K code and Write-Back cache - 4.5 million transistors - produced on an enhanced 0.35-micron CMOS silicon process which allows for a lower 2.8v voltage level - Socket 7 with VRM (321-pin processor socket) - MMX incorporates a process Intel calls Single Instruction Multiple Data (SIMD) - 57 new instructions (specifically to handle video, audio, and graphics data )

Pentium Pro (Fourth Generation Pentium)

Fourth Generation (Pentium Pro) - introduced in September of 1995 - 387-pin unit that resides in Socket 8 - Multi-Chip Module (MCM) physical format (Dual Cavity PGA (Pin Grid Array) package ) - 36.5 million transistors Processor Die contains 5.5 million transistors 256K cache die contains 15.5 million transistors 512K cache die has 31 million transistors - includes three internal instruction pipes - Built-in L2 cache - MPS allows configurations of up to four processors running together

Pentium Pro Processor Specifications Introduced:

September 1995

Maximum rated speeds:

150, 166, 180, 200MHz

CPU clock multiplier:

2.5x-3x

Register size:

32-bit

External data bus:

64-bit

Integrated-cache bus:

64-bit

Memory address bus:

32-bit

Maximum memory:

4G

Integral-cache size:

8K code, 8K data

Integral-cache type:

non-blocking, L1 cache

Number of transistors:

5.5 million

Transistors in L2 cache:

15.5 million (256K cache), 31 million (512K cache)

Circuit size:

0.35 micron

External package:

387-pin Dual Cavity PGA (Pin Grid Array)

Math coprocessor:

Built-in FPU (Floating-Point Unit)

Power management:

SMM (System Management Mode)

Operating voltage:

3.3v

    

                              

 

                             

Pentium II -

code name "Klamath May 1997 Single Edge Contact (SEC) cartridge Pentium II 266MHz chip is more than twice as fast as a classic Pentium 200MHz - a Pentium Pro with MMX technology instructions - 0.35 micron - incorporates Dual Independent Bus architecture (one for accessing the L2 cache, the other for accessing main memory )

CPU Type/Speed

CPU Clock

Motherboard Speed

Pentium II 233

3.5x

66

Pentium II 266

4x

66

Pentium II 300

4.5x

66

Pentium II 333

5x

66

Pentium II Processor Specifications Introduced:

May 1997

Maximum rated speeds:

233, 266, 300MHz

CPU clock multiplier:

3.5x,4x-4.5x

Internal bus width:

300-bit

External data bus:

64-bit

Integrated-cache bus:

64-bit

Memory address bus:

32-bit

Maximum memory:

64G

Integral-cache size:

16K code, 16K data

Integral-cache type:

non-blocking, L1 cache

Number of transistors:

7.5 million

L2 cache size:

512K

Transistors in L2 cache:

31 million

Circuit size:

0.35 micron

External package:

242-pin Single Edge Cartridge

Math coprocessor:

Built-in FPU (Floating-Point Unit)

Power management:

SMM (System Management Mode)

Operating voltage:

2.8v

Performance Headroom for the Applications You Need Whether you're into media, PC imaging, or communications, the Pentium II processor has plenty of special product features to meet your needs: 100MHz Front Side Bus (available with 450MHz, 400MHz and 350MHz) Dual Independent Bus architecture (D.I.B.) Dynamic Execution Intel MMX™ technology Single Edge Contact Cartridge (S.E.C.C.)

Fact Sheet

Two new features In fact the Pentium III contained two rather different news items, one small and one somewhat bigger. Intel's new top processor is a Pentium II in principle. It is mounted in a BX based motherboard with Slot 1. This processor has some built-in features: A rather problematic ID numbering. New registers and 70 new instructions. Finally the clock speed was raised to 500 MHz with room for further increases. Pentium III Xeon (code name Tanner) was introduced March 17th, 1999. It was a Xeon chip updated with all the new features from Pentium III. To utilize it Intel has the 840 chipset.

Processor Highlights   

- Speeds up to 2.20 GHz

  

- PGA-423 and mPGA-478 form factors

  

- Intel® NetBurst™ micro-architecture

  

- 0.13 or 0.18 micron technology

  

- Compatible with Intel® Architecture-based software

  

- Internet Streaming SIMD Extensions

  

- Intel® MMX™ media enhancement technology -System scalability up to 64 GB

  

- 400 MHz Front Side Bus of 128 bit width - 20 KB L1 cache and 256 KB L2 - The ALU (Arithmetical Logic Unit) runs at twice the clock speed

Processor Highlights ( continued) - A new socket for simple motherboard design - Clock frequencies from 1500 MHz - 20 stages pipeline - SSE2 and 128 bit MMX - 42 millions of transistors - A new 423 pins socket design - Dual Rambus memory channel with i850 chipset - Only single processor mode available.

NetBURST Intel uses the term NetBURST to describe some features in Pentium 4: Advanced Dynamic Execution The Rapid Execution Engine Advanced Dynamic Execution means that the processor may execute up to 6 instructions simultanously. Using Rapid Execution Engine certain instructions may be executed at twice the normal speed.

A 'Willamette' core Pentium 4.

"Northwood" core Pentium 4 processor. (P4A)

“Willamette” •1.4 and 1.5 GHz •released in November 2000 •Socket 423 , later revisions moving to socket 478 •100 MHz Quad-pumped (400Mhz FSB) •sacrificed per-cycle performance in order to gain two things: very high clockspeeds, and SSE performance •also comes in a low-end Celeron version (often referred to as Celeron 4) and a high-end Xeon version intended for SMP configurations. A 'Northwood' core Pentium 4 processor (P4A) •2.0 , 2.2 , 2.4, 2.8 GHz •3.06 GHz processor supported Hyper-threading (800FSB) •400 MHz to 533 MHz FSB •released in January 2002 •combined an increase in the secondary cache size from 256k to 512k •0.13 micron or 130nm) •socket 478 (socket 423 with adapters) •3.2 GHz variant was launched in June and a final 3.4 GHz version wa launched in early 2004

Extreme Edition 3.73 GHz - Top

Extreme Edition 3.73 GHz - Bottom

Pentium 4 Extreme Edition (P4EE) •2 MB of Level 3 cache •Socket 478 form factor , LGA775 version is also available •In office applications, the Extreme Edition was generally a bit slower than the Northwood •Some games benefited from the added cache, particularly those based on the Quake III and Unreal engines •improved most in multimedia encoding •bus speed from 800 MHz to 1066MHz •Only one Gallatin-based chip at 3.46 GHz was released before the Extreme Edition was migrated to the Prescott core

A ‘Prescott' core Pentium 4.

Prescott •90nm process •clocked at the same rate as a Northwood •benchmarks show that a Northwood runs slightly faster than a Prescott •Currently, 3.8 GHz is the fastest Prescott-based processor •from Socket 478 to LGA775 •LGA775 reference cooler and mounting system were somewhat better designs •thermal problems were so severe •Intel decided to abandon the Prescott architecture altogether, and attempts to roll out a 4 GHz •showed in extreme cases it took a 5.2 GHz Prescott core to match the performance of an Athlon FX-55 that clocked at 2.6 GHz

Dual Core Pentium 4

Dual Core Pentium 4 •marketed as the Pentium D 8xx •reputed to have a 60-80% increase in performance per clock-speed •launched May 2005 •Dubbed the “Smithfield” core •two connected Prescott cores

PC

CPUs

Year

Number of transistors

1st. Generation

8086 and 8088

1978-81

29,000

2nd. Generation

80286

1984

134,000

3rd. Generation

80386DX and 80386SX

1987-88

275,000

4th. Generation

80486SX, 80486DX, 80486DX2 and 80486DX4

1990-92

1,200,000

5th. Generation

Pentium Cyrix 6X86 AMD K5 IDT WinChip C6

1993-95 1996 1996 1997

3,100,000 --3,500,000

Improved 5th. Generation

Pentium MMX IBM/Cyrix 6x86MX IDT WinChip2 3D

1997 1997 1998

4,500,000 6,000,000 6,000,000

6th. Generation

Pentium Pro AMD K6 Pentium II AMD K6-2

1995 1997 1997 1998

5,500,000 8,800,000 7,500,000 9,300,000

Improved 6th. Generation

Mobile Pentium II Mobile Celeron Pentium III AMD K6-3 Pentium III CuMine

1999

27,400,000 18,900,000 9,300,000 ? 28,000,000

7th. Generation

AMD original Athlon AMD Athlon Thunderbird Pentium 4

1999 2000 2001

22,000,000 37,000,000 42,000,000

Graphic overview of the processors