Just like in any other Mac with 744x CPU, the speed is controlled by the jumpers. Here is the bottom of the board. Or whatever you call it. Many years ago there were component side and solder side. Now I don't know... But before you rush into it, take a look at the size of the jumpers. Read 7447's datasheet if you are interested. Jumpers are located in the area directly under CPU.



Link: Apple mini OC