Wikipedia:POTD column/March 21, 2006
The Intel 80486DX2 is a CPU produced by Intel that was introduced in 1992. The 80486DX2 is identical to a 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 slower than an Intel 80486DX-based system at the same processor speed.