Game Engine Black Book: Wolfenstein 3D:
Intel built two versions of the 386: the 386-SX and the 386-DX. They were identical processors yet the DX version was almost twice as powerful as the SX (on the chart the 386 Sx 33Mhz and the 386 DX 33Mhz are respectively at 5.1 and 8 MIPS). This is due to a data
bus between the CPU and the RAM being twice as wide on the DX (32 bits vs 16 bits).
Despite its inferiority, the SX sold well because it was cheaper and a lot of people had no
idea what a "bus" was, they just wanted "a 386".
This is exactly how my family ended up with a 386-SX. I recall Amin later explaining to me why this was bad.