 It was the first 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.For many players of video games during the early and mid 1990s, towards the end of the MS-DOS game era, the i486DX2-66 was a very popular processor.