If it comes to no sleep I can push myself for about 3 - 4 days before I begin to feel like I'm physically dying, probably am. If however I get like 2 hours on the 3rd night you can generally add another full day or two to the mix without me wanting to die but I'll sleep like a log for 24 hours at the end of it. I'll generally also begin hallucinating about crap.

If we're talking my normal sleep pattern, I tend to sleep like 3 - 5 hours a night every night depending on how healthy I'm feeling when ill I sleep longer.