Intel Corp rates the 66MHz version of the Pentium chip at 112 MIPS – well it is claimed to execute two instructions per cycle – one for each of its parallel arithmetic-logic units – two five-stage execution units, and claims that it is five times more powerful than the original 80486 microprocessor and over 300 times faster than the 8088; it contains 3.1m transistors, compared with 1.2m for the 80486; it is manufactured in Intel’s 0.8 micron three-metal layer BiCMOS process technology; it has two 8Kb on-chip caches and a fully compatible floating point unit that is up to five times faster than the one on the 80486 at the same clock speed; to get around the problem that the thing can squeal to a halt when it comes to a branch that stalls the instruction stream, it includes branch prediction, where the chip remembers prior instruction pathways and predicts the correct pathway for a new instruction.
