What are the differences between the Intel 80386 and the Intel 80486?

Answer 1

* Data/Instruction Cache - An 8192-byte SRAM built into the processor core, designed to store the most commonly used instructions. The 386 supported an off-chip cache, but this was much slower. * Pipelining - This allows the processor to handle a Locate-Fetch-Execute each clock cycle. The pipeline is offset meaning the execute step required information from the previous two clock cycles. A locate would feed the next fetch, the fetch would feed the next execute. The 386 needs to do each step separately. * Improvements to MMU performance. * Integrated FPU - (DX models only) Added accelerated high end math functions.

Answer 2

The 486 had on-chip cache, a better memory management unit, and (most important) an integrated math coprocessor. A really hot 386-based computer would have had an 80386 CPU, an 80387 math coprocessor and 8 kilobytes of on-chip cache memory. The 80387 math coprocessor was more expensive than the 80386 main processor (which was very expensive itself) so about the only people who had one were AutoCAD users, and they only had one because AutoCAD wouldn't start if the 80387 wasn't there. By integrating all three functions on one chip, computer builders could make better computers with smaller chip counts.

Answer 3

The 8088 processor is slower than the 8086 processor, for equivalent bus clock speeds. The 8086 accesses memory two bytes at a time, while the 8088 accesses memory one byte at a time.

Answer 4

No.