And you really shouldn't.
"CX" line of PSUs is the worst that Corsair offers on the market these days.
You can be quite alright with "TX" line's PSU, you can definitely buy and use any of the "HX" line, you will be a definite GOD with any of the "AX" line of PSUs...but never (NEVER!) get any of the "CX" or "GS" PSUs, they are absolute garbage!
If you're very tight on the budget, then get AT LEAST "TX" Corsair PSU, you won't be disappointed. But no matter what - don't get "CX" or "GS", they are the worst trash you can buy these days!
And again - if you're THAT tight on the budget that you can't even afford 650W "HX" (which is not very expensive, especially considering it's high-level quality and performance), then I highly recommend that you get this
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139020 one, it's pretty good too.
BTW: "C" in "CX" stands for "CRAP". >: )