Listed below is a summary of Intel's CPUs along with some of their specifications:

CPU	Date	Max Addrs Mem	Word Size	Bus Width	Math Coprcsr	Speed MHz
8088	1979	1 MB	16-bit	8-bit	No	4-8
8086	1978	1 MB	16-bit	16-bit	No	4-8
80286	1982	16 MB	16-bit	16-bit	No	6-20
80386SX	1988	16 MB	32-bit	16-bit	No	6-12
80386DX	1985	4 GB	32-bit	32-bit	No	16-33
80386SL	1985	16 MB	32-bit	32-bit	No	25
80486SX	1991	4 GB	32-bit	32-bit	No	16-50
80486DX	1989	4 GB	32-bit	32-bit	Yes	25-100
80486DX2	1992	4 GB	32-bit	32-bit	Yes	40-80
80486DX4	1994	4 GB	32-bit	32-bit	Yes	75-120
80486SL	1989	4 GB	32-bit	32-bit	Yes	25-50
Pentium	1993	4 GB	32-bit	64-bit	Yes	60-200
Pentium Pro	1995	64 GB	32-bit	64-bit	Yes	133-200