Sam - In your experience, how much time does it take for founders to get rid of a co-founder who isn't performing up to par? Is it a decision by consensus? Or

Sam - In your experience, how much time does it take for founders to get rid of a co-founder who isn't performing up to par? Is it a decision by consensus? Or does the CEO take the call? How do they evaluate each other when everyone is an expert in his/her own domain? I would love to know how successful startups have dealt with these situations, and if you can share any experiences, that would be very helpful, since fights between co-founders are a major reason startups fail.