I'm going to be doing an almost complete system upgrade soon buying a new CPU, motherboard, RAM, and video card. What I plan on getting is a Core i5 2500k, 8 gigs DDR3, a motherboard I haven't decided on yet, and either a GTX 560 Ti or 570(just one for now, but within another month or two will get a second one for SLI).
You are correct in that the 650w will be enough for now but certianly not for when you get the second video card especially if is a 570. You may want to go with a 850w just to make sure and you can never have too much watts. The good thing is that if you know you will be doing SLI , then between now and then you can be on the lookout for a sale on psu's and try to catch a good deal.
For a system using two GeForce GTX 570 graphics cards in 2-way SLI mode NVIDIA specifies a minimum of a 800 Watt or greater power supply that has a combined +12 Volt continuous current rating of 56 Amps or greater and that has at least four 6-pin PCI Express supplementary power connectors.
For a system using two GeForce GTX 560 Ti graphics cards in 2-way SLI mode NVIDIA specifies a minimum of a 700 Watt or greater power supply that has a combined +12 Volt continuous current rating of 44 Amps or greater and that has at least four 6-pin PCI Express supplementary power connectors.
Your Antec EarthWatts Series 650 (EA 650 - EC), with its combined +12 Volt continuous current rating of 45 Amps and with one 6 pin and one 6+2 pin PCI Express supplementary power connectors, is only sufficient for a single GeForce GTX 570 or a single GeForce GTX 560 Ti.
Adding a second graphics card requires two more PCI Express supplementary power connectors and more +12 Volt rail capacity.
Thanks for the help guys. Seem like my assumption was correct.
Good to know that I can make due with what I have now and not have to worry about a PSU upgrade until it comes time to add the second card. That way I can hold off until I see a good deal to snag somewhere.
Even though it's not in my immediate plans, I might even grab one in the 900-1000W range so I have the available power should I decide to throw in a dedicated Physx card too(which isn't totally out of the question)
Like I said it's always good to have extra watts and you just posted why that is true , you never know what you are going to add and it would be a pain to have to change the power supply everytime you want to add something.