Intel 8088 In 1981 the original IBM PC was released. The CPU which powered the PC was an Intel 8088 running at 4.77MHz. That means the internal clock ticked 4.77 million times each second. Over the next 24 years the clock speeds of PCs rose consistently and rapidly. For PC enthusiasts the old speeds are a trip down memory lane: 12MHz, 25MHz, 33MHz, 66MHz, 90MHz, 133MHz, 300MHz, 600MHz, 1.2GHz, 2.4GHz.
