Pentium microprocessor

The Pentium microprocessor is a brand of single chip computer that was introduced in 1993 by integrated circuit manufacturer Intel. It was the fifth generation of the x86 series which had begun in 1978 with the Intel 8086. It was considerably more powerful than its predecessors which had less than ten thousand transistors incorporated on their surfaces – the earliest Pentiums had over a million.

Competing manufacturers had brought out pin compatible chips which had the same names as the Intels and, as they executed the same instruction set, could be substituted for them. The next chip in the Intel series was to be named the 80586 but Intel chose to call it the Pentium as the name could be trade-marked to stop competitors from copying it. The most successful rival to the earliest Pentiums was the AMD K6 series.

Intel named their succeeding chips the Pentium 2, Pentium 3 and Pentium 4. The original is now called the Pentium microprocessor. After Pentium 4, the last generation of the family (released in 2005) was named Pentium D. The later Pentiums ran at faster clock speeds, included more on-chip cache memory, and a few additional instructions.

A Pentimum that ran at 90 or 100 megahertz was introduced on March 7, 1994. This chip was not pin-compatible with the earlier model, because it required two power inputs. All subsequent Pentiums required a second power input at a lower voltage. Part of the chip functions at a lower voltage to keep down the overall power consumption and heat generation. The last model in this series, introduced in 1996, consumed 15 watts when running at 200 megahertz. These Pentiums incorporated 3,200,000 transistors.

A third model of the original Pentium was introduced on January 8, 1996. It was sometimes called the "Pentium MMX", because it implemented a small additional subset of instructions that were designed to make multimedia applications more quickly transfer large blocks of sound or video data. It incorporated 4,500,000 transistors and the 233 megahertz version consumed up to 17 watts of power.