CPU design approach in general splits into 2 most important branches:
- CISC architecture — design with complex instructions set
- RISC architecture — design with small set of simple instructions
Intel (upto Pentium 4)
Intel processors are all CISC.
| Main feature | Timeline |
|---|---|
| 4 bit | 4004 (1971) → 4040 (1974) |
| 8 bit | 8008 (1972) → 8080 (1974) → Z80 (1976) |
| 16 bit | 8086 (1978) → 8088 (1979) |
| 32 bit | 80386 (1985) |
| High Perf | 80486 (1989) → Intel Pentium (1993) |
| Multi-core | Pentium Pro (1995) → Pentium 2, Pentium 3 → Pentium 4 (2000) |
Features that new processors introduced:
| Processor | Featuer |
|---|---|
| 8086 | first x86 architecture |
| 80486 | pipelining |
| Pentium | superscalar architecture, dual pipelines |
| Pentium Pro | superscalar, L2 cache on-chip |
| Pentium 2/3 | MMx, SSE instructions |
| Pentium 4 | Hyper-Threading, NetBurst architecture |
Notable competitors (CISC):
| Year | Description |
|---|---|
| 1975 | 6052, competitor of 8080, widely used in gaming consoles |
| 1979 | Motorolla 68000, Popular in Macintosh/Atari/Amiga, 16/32 bit |
| 1999 | AMD Athlon (CISC x86), competitor of Pentium 3 |
| 1990s | AMD K5/K6 (CISC x86) |
RISC
| Year | Description |
|---|---|
| 1981 | MIPS |
| 1985 | ARM |
| 1987 | SPARC |