What power supply should I have for GTX 480?

[niknovacain]

I just ordered a Corsair HX750 and am second guessing that maybe I should get the 850 instead.

Here is my system (Not built yet):
Core i5 2500k or 3570k (undecided)
Crucial M4 64 GB
WD Caviar Black 1TB
8 GB G.Skill 2x4
GTX 480
Samsung Blu Ray Drive
Corsair 500R Carbide Case w/ 2 extra Cooler Master Case fans
Cooler Master 212 Evo
Asus P8Z77 V-Pro
27'' Samsung monitor

I have done some research and apparantly the GTX 480 runs at almost 390W under full load. I am wondering how people found these numbers. I am new at this, any help is appreciated.

On paper the card requires minimum +12V current of 42A. The HX750 has 62A single rail. So, on paper, the hx750 will run the card just fine. I am wondering if there are any extra variables that people with more experience know of?

 

[niknovacain]

Thanks for the reassurance. I am pretty paranoid as a first time 'to be' builder. I like the (partial) modular design of the corsair. And I like it to match my case because I am very weird OCD like that. Thank you nonetheless for your input.

 

[niknovacain]

Best answer selected by niknovacain.