Intel 80486DX2

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The Intel 80486DX2 is a CPU produced by Intel that was introduced in 1992. The 80486DX2 is identical to the 80486DX but for the addition of "clock doubling" technology. It was the first chip to use clock doubling, whereby the processor performs two clock cycles per single cycle of the memory bus. Essentially, the processor's speed is set to double of the speed of the system bus. Because of this, an Intel 80486DX2 is faster than an 80486DX-based system at the same bus speed; a normal DX chip performs one processor clock cycle per system bus cycle, while a DX2 chip performs two processor clock cycles per bus cycle.

It is now standard practice for a CPU to perform more than one clock cycle per bus clock cycle.

For many players of video games during the early and mid 1990's, towards the end of the MS-DOS gaming era, the 80486DX2-66 was a very popular processor. Often coupled with 8 - 16 MiB RAM and a VLB video card, the CPU was capable of playing every title available for several years after its release, making it a "sweet spot" in CPU performance and longevity. The introduction of 3D graphics spelled the end of the 486's reign, because of its heavy use of floating point calculations and the need for faster cache and more memory bandwidth. Developers also began to target the Pentium almost exclusively with assembly optimizations (i.e. Quake).

AMD and Cyrix both produced 486-level competition for the Intel 486DX2.

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