This is perhaps more of a discussion question, but I thought stackoverflow could be the right place to ask it. I am studying the concept of instruction pipelining. I have been taught that a pipeline's instruction throughput is increased once the number of pipeline stages is increased, but in some cases, throughput might not change. Under what conditions, does this happen? I am thinking stalling and branching could be the answer to the question, but I wonder if I am missing something crucial.