Performance of microkernel vs monolithic kernel. As is always the answer (or at least the preface) to performance-related questions: know your problem domain, run comparative benchmarks, and remember what premature optimization is.
A summary of the difference between contactors, motor starters, relays and circuit breakers. Switches, circuit breakers, and contactors are used to control what parts of an electrical system are energized or de-energized. Fuses are used to protect the electrical system when something goes wrong, and can isolate the faulted parts from the normal parts.
MORE breakers or fuses serve to automatically shut off power to the circuit wires if something goes wrong. In the case of circuit breakers, the immediate answer is to find the breaker that has tripped and reset the lever to the ON position. With a fuse, a metal filament inside the fuse has burned through, and you'll need to replace the fuse with a new one.