[logical42]

I think you're likely to get a variety of ranges from the answers here, due to natural biological variation. I can't say for sure, but I suspect that the common theme here will end up being that people do feel that the number of hours that they sleep is important in how it affects their work (which is reasonable, since the act of coding is a mentally strenuous act).

I'm a bit curious now, I wonder how many people here try to wake up naturally.. personally, I consider that to be pretty reliable in forecasting my day's productivity.