750W or 650W

[Chasingu]

Well, Im looking at buying either an AX750w or a AX650W.

I have two questions, based on my hardware below, what power supply should I get.
The other question is, what power supply is the best of the best, I know the AX750W uses parts from Seasonic, but does the 650W also use it?

I know there isn't much of a difference of 100w, or at least I don't think there is, but seeing as when the school year rolls around and this Machine will be cruching BOINC during the night and when Im at school, that is around 15 hours of 100% CPU and GPU load, and I would like to keep the energy bill low by using an optimised power supply.

So, AX650w or AX750w, and do both use Seasonic parts?

Rig:
Processor: Intel Core i5 3570K Quad-Core (Stock Settings)
Motherboard: ASUS Sabertooth Z77
RAM: 16GB Corsair 1333MHz XM3
Hard Drive: 1TB
Processor Cooling: Noctua NH-D14
Graphics Card: MSI Radeon HD 7850 Twin Frozr III OC
Monitor: Dell - ST2220L 21.5-inch Wide LED Flat Panel Monitor
Keyboard: Logitech G510
Mouse: Logitech G9X
Case: Corsair 600T SE White

[ilya]

I would go for a Seasonic x-560 or the AX650 if you want the better customer service, you'll only be pulling ~200-250W at full GPU/CPU load.

Aside from the AX1200, all the Corsair AX series units are Seasonic built.

[Masteroderus]

As long as you're not planning to do SLI or run a dual GPU card I think 650 watts is plenty. 560 watts should also be plenty.

Aside, I think power consumption of desktop PCs is going to be on a downward trend as power costs rise in north america.

[horusray]

I got a 750w psu in case an opportunity for sli/xfire opens up...