In 1989, Intel announced shipment of the 80486 chip.
The Intel 80486 microprocessor (alias i486 or Intel486) was a higher performance follow up on the Intel 80386. It was the first x86 chip to use more than a million transistors, due to a large on-chip cache and an integrated floating point unit. It represented a fourth generation of binary compatible CPUs since the original 8086 of 1978. A 50 MHz 80486 executed around 40 million instructions per second on average and was able to reach 50 MIPS peak.
Learn more at http://en.wikipedia.org/wiki/Intel_80486