The minimum requirement for the reference design of the GTX 670 is 500 watts, but I am going to buy a factory overclocked version. Some of the 670 models have a 550 W power requirement, while others stick with the 500W.
My question is, is it safe for me to rely on this PSU and go ahead with the purchase? Or do I need to invest in a bigger PSU?
For GTX 670 you'd better get an "600~650W"-level PSU at least, and preferably with at least "Bronze"-level of efficiency.
Some 550W PSUs can feed GTX 670 just fine, but will be simply capped, which is no good at all. You definitely need that little extra with these beasts.
I can recommend you a couple of very solid PSUs, if you do decide to hop onto "6xxW" mark.
I'm using a 670 at 1254Mhz, on a 500w PSU. Unless your CPU pulls a stupid amount of power its fine. The power requirements are intentionally inflated so people with $10 power supplies don't blow their computer sky high.
I'd like some recommendations on 600-650W PSUs please.
Alright, but before that tell me, you're going to use only microcenter as the place where you'll be buying? Because I'd rather do it at Newegg or NCIX.
Anyway...here's my personal recommendations for you: get this or this. These two are quite solid choices (for your money, that is) that will completely satisfy your demands.
If you can get them from microcenter, then it's fine. I just don't like microcenter because usually it has boring and rather small menu.
Honestly, I'm pretty sure I'm gonna go with microcenter because it is so damn close, there's no shipping fees and also, if anything goes horribly, terribly wrong, I won't have to deal with waiting around for a number of weeks while Newegg ships a new product to my doorstep.