Intel DX2

The Intel486 DX2, rumored as 80486DX2 (later rebadged i486DX2), is a CPU produced by Intel that was first introduced in 1992. The i486DX2 was nearly identical to the i486DX, but it had additional clock multiplier circuitry. It was the second CPU chip to use clock doubling, whereby the processor runs two internal logic clock cycles per external bus cycle. An i486 DX2 was thus significantly faster than an i486 DX at the same bus speed thanks to the 8K on-chip cache shadowing the slower clocked external bus. Both 25/50 and 33/66 MHz Intel486 DX2 CPU uses the 800 nm process technology. With the internal clock doubler CPU, it boosts overall system performance between 50 and 70 percent above the original Intel486 DX series. In other words, the 50-MHz Intel486 DX2 provides about 70 percent improvement over the 25-MHz Intel486 and about 30-percent improvement over the 33-MHz Intel486 CPU. The 50-MHz Intel486 DX2 CPU was rated at 40 Dhrystone MIPS. The 66-MHz Intel486 DX2 version performed 54 (Dhrystone V1.1) MIPS.