80386

The 386 was available in speeds ranging from 16-40Mhz (not including a few rare chips that were faster), and in two flavours the SX and the DX. Both were 32-bit chips, but the SX used a 16bit motherboard bus which slowed down its performance (but saved money). Most programs require at least a 386 to run (as they were the first 32-bit x86 processor).

• Intel 386's ranged from 16-33 mhz
• AMD's ranged from 16-40Mhz
• Cyrix and IBM (and also TI???) also manufactured 386's

Coprocessors were available for the 386, they were called 387's, and were also manufactured by several companies, they had to run at the same clock speed as the 386, some companies produced a faster 387 than others (at the same clockspeed).. the IIT 3C87 is an example