AMD Am386 DX40

The fastest 386 ever made! It runs at a whopping 40MHz which means it also uses a 40MHz bus. This together tremendously increases the speed of the computer. Combine it with a Vesa Local Bus graphics card and I think it can be faster than the budget, but more expensive, 486 systems.

AMD released this 40MHz part at the time when the 386 was mature. Motherboards were more advanced and could be build with a few components (opposed to the older big motherboards which have a lot of little chips). Those motherboards could run at 40MHz without causing trouble with latencies.