|Really Really Need Answer Out Of These 2 PSU'S

550 watts is cutting it close with overclocking and so many fans. So I would get at least a 600 watt to be on the safe side. You can get a better idea by using "extreme power supply calculator"
 



Hi - The 1st one - XFX 550 is more than sufficient for your
System and the 650 is priced too high relative the 550, and
I 2nd Brett's suggestion of buying from scan vs ebay, much safer

Tom

Actually, go for the 650 if you can - I missed the dbl OC
 



Hi again - plz see below (from Hardcore-Gamers website) the reason I upped my suggestion to
650w after I noticed the OC'ing of cpu & gpu you will be doing.

You don't have to agree with it, but just be aware of it.

CONCLUSIONS
Looking at power supplies, the most desirable feature is a single 12V circuit with adequate capacity. Careful checking for a suitable PCI Express connector set is vital for gaming grade video cards. Modular cables are desirable but expensive.
Using a PSU with 2x the capacity of the active gaming load will be at the peak of efficiency curve. This is why nothing under 650 W is suitable in a gaming machine, especially if overclocking is desired.
We would be happier if all PCI Express cables were simply 6-8 pin so that 2-way users have adequate resources for dual GPU cards. Providing 6 cables is feasible on a single rail PSU to support 3-way single GPU cards and 2-way dual GPU cards easily. Many 1200 W power supplies still ship with 6-pin connectors. A dual GPU setup in SLI/CFX provides a 4-way machine that can play games on ultra for several years to come.

http://www.hardcore-games.tk/wp/hw/psu.php

Tom

 

That's sad