Check the review of the Graphics card in different sites. Although they use very high end Processors during testing, you'll get a rough idea about how much FPS your card can provide at different games with different settings. For example, in review, you found out that HD 7770 can provide around 40 FPS at 1080P resolution when being used with a i7 3770 and you ar having an i3 3220 Processor. Then expect something like 30 to 32 FPS in your case. Now run Fraps and check actually how much FPS you're getting. If it very low, occasionally goes below 20 FPS, giving you a choppy experiece, then something is bottlenecking the card.