The 4004 CPU was the forerunner of all of today’s Intel offerings and, to date, all PC processors have been based on the original Intel designs. The first chip used in an IBM PC was Intel’s 8088. This was not, at the time it was chosen, the best available CPU, in fact Intel’s own 8086 was more powerful and had been released earlier. The 8088 was chosen for reasons of economics: its 8-bit data bus required less costly motherboards than the 16-bit 8086.
Also, at the time that the original PC was designed, most of the interface chips available were intended for use in 8-bit designs. These early processors would have nowhere near sufficient power to run today’s software.
The table below shows the generations of processors from Intel’s first generation 8088/86 in the late 1970s to the eighth-generation AMD Athlon 64, launched in the autumn of 2003:
Chronological Evolution of CPUs
| Type/
Generation |
Year | Data/
Address bus width |
Level 1 Cache
(KB) |
Memory
bus speed (MHz) |
Internal
clock speed (MHz) |
|---|---|---|---|---|---|
| 8088/
First |
1979 | 8/20 bit | None | 4.77-8 | 4.77-8 |
| 8086/
First |
1978 | 16/20 bit | None | 4.77-8 | 4.77-8 |
| 80286/
Second |
1982 | 16/24 bit | None | 6-20 | 6-20 |
| 80386DX/
Third |
1985 | 32/32 bit | None | 16-33 | 16-33 |
| 80386SX/
Third |
1988 | 16/32 bit | 8 | 16-33 | 16-33 |
| 80486DX/
Fourth |
1989 | 32/32 bit | 8 | 25-50 | 25-50 |
| 80486SX/
Fourth |
1989 | 32/32 bit | 8 | 25-50 | 25-50 |
| 80486DX2/
Fourth |
1992 | 32/32 bit | 8 | 25-40 | 50-80 |
| 80486DX4/
Fourth |
1994 | 32/32 bit | 8+8 | 25-40 | 75-120 |
| Pentium/
Fifth |
1993 | 64/32 bit | 8+8 | 60-66 | 60-200 |
| MMX/
Fifth |
1997 | 64/32 bit | 16+16 | 66 | 166-233 |
| Pentium Pro/
Sixth |
1995 | 64/32 bit | 8+8 | 66 | 150-200 |
| Pentium II/
Sixth |
1997 | 64/32 bit | 16+16 | 66 | 233-300 |
| Pentium II/
Sixth |
1998 | 64/32 bit | 16+16 | 66/100 | 300-450 |
| Pentium III/
Sixth |
1999 | 64/32 bit | 16+16 | 100 | 450-1.2GHz |
| AMD Athlon/
Seventh |
1999 | 64/32 bit | 64+64 | 266 | 500-2.2GHz |
| Pentium 4/
Seventh |
2000 | 64/32 bit | 12+8 | 400 | 1.4GHz-3.6GHz |
| AMD Athlon 64/
Eighth |
2003 | 64/64 bit | 64+64 | 400 | 2GHz-2.4GHz |
- Principles of CPU architecture – logic gates, MOSFETS and voltage
- Basic structure of a Pentium microprocessor
- Microprocessor Evolution
- IA-32 (Intel Architecture 32 ) – base instruction set for 32 bit processors
- Pentium P5 microarchitecture – superscalar and 64 bit data
- Pentium Pro (P6) 6th generation x86 microarchitecture
- Dual Independent Bus (DIB) – frontside and backside data bus CPU architecture
- NetBurst – Pentium 4 7th generation x86 CPU microarchitecture
- Intel Core – 8th generation CPU architecture
- Moore’s Law in IT Architecture
- Architecture Manufacturing Process
- Copper Interconnect Architecture
- TeraHertz Technology
- Software Compatibility
- IA-64 Architecture
- Illustrated guide to high-k dielectrics and metal gate electrodes