Hey guys i am considering to upgrade only my gpu and psu for my current pc which is a k320 Lenovo. it has a i7 870 cpu, L-IIBXM v1 motherboard, 8gb ram, and i playing on a 1080p led single monitor but i may get a 120hz 1080p monitor in the summer/fall. Looking to buy either a gtx 770 or 780 or even waiting for the 8xx series if it hopefully the price of those will be similar to 770/780. Idk if my cpu will bottleneck 780 other betters ones (Maxwell). Anyway my budget is pretty much the price of a gtx 780 since i am planning on buying a psu with that and also maybe a case and ssd. however, if the jump between the 770 to 780 is not worth the extra money then i rather not go that far. I play games such as WoW, hearthstone, Diablo, Southpark, and looking forward for games such as titanfall, dark souls 2, dragon age, elder scrolls and few others. Also, I do not want to SLI so at all because i am not the one that pay the bills at my house and prefer a single gpu. Thanks!!