What is the prefetch buffer?
The prefetch buffer can be used to get bytes from game ROM before you actually need them. It only works for ROM and not other forms of memory and it is off by default. The advantage of turning it on is that it will prefetch ROM data while the bus is idle. This allows some sequential accesses to occur at 0 wait states. The disadvantage of turning on prefetch is that it uses ~10% more battery power.
