nvidia gt640 and 4k

So I have read people complaining about lack of 4K 60Hz but 4K 30Hz seems to be working correctly. I just ordered a vizio 70" 4K TV (http://www.amazon.com/VIZIO-M70-C3-70-Inch-Ultra-Smart/dp/B00T63YVAM) and am curious if my sandy bridge (nvidia GT640, i5 2500k, 16GB, GA-H61M-USB3-B3 hackitosh...