It depends on many things, choosing a card is not depend on PSU only, there's so many things like your CPU, RAM, Mobo, PSU, Monitor, Budget.
Also, a cheap 460W PSU can deliver different power if you compare it with a decent(bit expensive) 460W PSU (Corsair, Antec, Seasonic, PCP&C, SilverStone).
Take a look at this:http://www.newegg.com/Product/Product.aspx?Item=N82E16814125363
GTX 560 Ti
That card required 500W PSU with 2x6pin power connector. With a decent PSU (even 460W PSU) you can run that card flawlessly, but with a cheap 460W PSU I doubt it...