It completely depends on your expectations and budget. If you're not expecting to play at ultra settings, another GTX 650 might be what the doctor ordered. If you're more or less happy with your current performance, even two (very weak) GTX 650 cards in SLI would make you happy. They will more or less equal the performance of the HD 7870 which costs almost $200. If you don't plan to play BF4 at Ultra settings, then two GTX 650s will probably do the job just fine. I always say "Pay as little as possible for as much as you can get for right now because you'll be upgrading it sooner or later." which is why I believe that SLI or Crossfire is the best upgrade you can do because you still leverage the power of the card you already paid...