Is my PSU good enough to run a GTX 670, or will I need to upgrade?

The PSU I currently have is an Antec EA-650. Based on NVidia's minimum requirements of a 500W PSU, and 30A rating on the +12V rail, I'm wondering if my current PSU would be good enough, or if I should upgrade.

I'll go based on the specs on my box, because looking up the model number EA-650, brings up two PSU's that have different specs than mine.

Anyway, on the box it reads:

+12V(1) - Max Load: 22A
+12V(2) - Max Load: 22A
+12V(3) - Max Load: 25A

+12V(1), +12V(2), +12V(3), combined max output 540W.

The other EA-650 specs that I found online, one has 38A/38A, and the other has 30A/30A/30A. I don't know why, with the same model number as mine, they have different specs...although EA-650 isn't very specific, but would mine be good enough with the on-box specs, or no?

I'm just not sure if I should combine the three +12V rails to get the total, or if I just go by the one which has the max, which would be 25A, and not meet the minimum requirement on the NVidia site of 30A.

My other specs as well, if they will matter:

-Intel Core i5-3570k
-8GB's DDR3 @ 1600MHz
-128GB SSD (Main System)
-500GB/1TB Additional HDD's for storage.
-Blu-Ray Player
-DVD/CD Player/Burner
-Gigabyte Z77X-UD5H Motherboard
-5 Case Fans (2x200mm, 3x120mm)
-HyperCooler 212 Plus (CPU Cooler)

So, would my current Antec EA-650 (650-Watt) be able to run a GTX 670, on top of my other specs, or should I upgrade. And if I do need to upgrade, do you have any suggestions?

Thanks!