Ok mabye not so scary 
I guess the scariest part is telling my wife I'm buying one........
I guess the scariest part is telling my wife I'm buying one........450 watts is cutting it close if you're going to overclock... which you will want to since it's so easy. Why not buy a 1000+ watt PSU? You're going to want a second S1 anyways.
But seriously, don't skimp on the PSU and buy cheap. You'll likely regret it.
I'm not sure about overclocking my u1's get lots of hardware errors and rejects but will get 500w or more PSU maybe will get the 1000w ?