well don't expect a miracle so maybe look at a 7750 or cheaper the 6670 or cheaper the 6570 or cheapest 6450 all will make your 7300 feel like a really old. They all do not require additional power cables just like your current card and it is about the best you can do but your cpu is very slow so do not expect a night and day change as the cpu will hold back 6670 and 7750