I don't think those older 775's can take DDR3.
My guess, looking at those specs, is that he recently upgraded his video card from something like a 8800gt to the new 460 and isn't seeing much in the way of fps increase.
From my research, looking to upgrade my 9800gtx+ sli setup running on an evga 780i board, I needed to get an i3 or i5 to make use of the new video cards (6850, 570, etc). That is probably what you'll have to do as well. So keep the 460 and use it in a new build.
Well, a few months ago, I made a thread about Battlefield Bad Company 2, and why I still get pretty much the same framerates after I upgraded to a quad core and a DX 10 card, then a DX 11 card a year and a half later. I went from a GTS 250 to a GTX 460 back in February. And the game still runs like crap even on the lowest settings.
So I was thinking maybe my RAM was the problem. Basically what I want to know, is if faster RAM, such as 1066mhz, would make much of a difference when playing a video game.