I am currently running this system for gaming:
ASROCK 880GMH/u3s3 mobo
HD6770 video card
600w (on label) psu
When I play BF3, after 5 minutes or so of steady gameplay my CPU goes to 100 usage and the game has terrible FPS, it corrects itself after about 2-3 minutes.. I have determined I need a new CPU and need to know if my computer can handle a AMD Phenom II X4 965 Black Edition (30 watts more than the current fx) or if i will need a psu upgrade..
+1^ try Antec, XFX, Seasonic, Pc Power and Cooling, Corsair etc. However despite your cheap power supply, you are way under 600 watts and 30 watts will not do much. SO you are most likely good to go with a CPU upgrade without a new power supply. However I urge you to no longer use cheap power supply brands, look at this list for good power supplies:
Based on the list try to stay above tier 3, never go into tier 4 or 5.
Edit: Just to clarify, I am not saying your power supply can put down 600 watts but it will put down around 400-500 watts which is typical for a cheap power supply despite the label. 400-500 is more than enough for that build given you don't use a lot of DVD Drives and hard drives. If you want an actual wattage (estimation) then I need how many dvd drives and hard drives you use, and any other peripherals connected via motherboard (PCI). Also did you mean Coolmax for the brand of your power supply? Don't think i've heard a coodmax...
Anyways never ever skimp on a power supply(unless it's your enemy's computer) in the future if you want to keep your computer in tip top shape. Your current power supply may not have over voltage protection and other essential safety features that quality power supplies have.