title: Why speedup reduces with increase in number of pipeline stages?
body: <p>I am watching a video tutorial on pipelining at <a href="http://www.youtube.com/watch?v=S_BQHUB1IsU&amp;list=PLD8AF625E53B0691F" rel="nofollow">link</a>.</p>
  
  <p>At time 4:30, the instructor says that with increase in number of stages, we need to also add pipeline registers, which creates overhead, and due to this speedup cannot increase beyond an optimal value with increase in number of stages.</p>
  
  <p>Can someone please elaborate this ? My doubt is that the pipeline register might be adding some delay to individual stage cycle time, so why does it become a problem when number of stages are large compared to a few ?</p>
  
  <p>Thanks.</p>