Assuming your current card is a 4670, it's not enough of a boost to see a significant difference (according to the chart). But I may have your card wrong so take a look yourself.
Bears in mind asking as well - which game are you playing? You may not see much of a performance boost with the low-enders like WoW or FFXI, but the newer more hi-rez games may have some performance benefit with the better card.
I have the 6670, and it's really good. I can run most games on almost maxed out settings. I defiantly suggest upgrading to the 6670. ______________________ coupons dell