System Specs:
Processor: core i5 2500k @stock speed
Mobo: ASUS P8 Z77 VL-K
RAM: 8GB 1600MHz.
I don't usually do any overclocking and stuff like that .....
Dude I have the same cpu and it`s not that power efficient as the newer ones... So I would say the 450 is a little too much on the wire, just go for a good quality 550W+ PSU and you should be fine!