The original 1GB gtx460 and HD6850 are about the same. HD7770 was a little slower at launch than HD6850, but newer drivers have boosted
performance notably. Hardocp found that a mildly OCed xfx 7770 provided the same gameplay experience as both HD6870 and gtx560ti :http://hardocp.com/article/2012/02/14/x ... ed_review/
If you read the BF3 page, you will see they were able to frag people online on ultra(using fxaa instead of 4xaa, turning off motion blur for both
better frame rates and to see their surroundings better, and bumping ambient occlusion down a notch from horizon based to screen space) at
1920x1200. The also overclocked it even higher later on. That was with launch drivers. All GCN Architecture cards are faster now than they
were at launch. Also hd7750 is 55w(stock, fits within the PEG slot's power envelope), hd7770 is 80w, gtx550ti is 116w(slower than hd7770 and
similar nowadays to hd7750), hd6850 is 130w, hd7850 is 130w(stock),gtx460 768 is 150w, hd6870 is 151w, gtx560 is 150w, the original gtx460
1GB is 160w, gtx 560ti is 170w and hd7870 is 175w(gtx650 is 65w and slower than hd7750). Some of the older cards overclock better than
others, but all the new 28nm cards oc like crazy. Also, some games are taking advantage of more than 1GB of video ram now, so if you go with
a hd7850 get one of the majority with 2GB GDDR5 and not one of the minority with only 1GB. Games using more vram will only become more
prevalent as time passes. Finally, what is your PSU? I wonder if maybe the aging process is making it deliver less power to your gtx460 and
causing your visual problems(depending on the quality of psu and wattage rating/+12volt amps). If that is the case, you may need to look for
a card with less wattage like the hd7770. Either that or possibly upgrade to a newer, better psu if you want a more power hungry card.
Oh, yeah. All hd7770s are ghz editons. It was the first reference video card from either nvidia or amd to have all functional units on the gpu
die operating at at least 1ghz. And hd7770 was similar to gtx460 768/hd6790 at launch. It's faster now. Any overclocking on your part will
increase power usage. Power use increases linearly with clock speed increases, but exponentially with voltage increases.