GTX460 performace problems

Well folks my first topic and already is on problem
Last month I did a little UP for a 1gb ZogisGTX460 with a Q9400 instead of an E8500 with XFX 9800GTX, because Game 2 BF bad company, because he play a lot online and need a quad with a vga best to run it smooth.
But it has not changed the performance is virtually the same, my FPS are the same with the 9800 average and in some points of the game dropped to 20fps.
Ja did everything, formatted the pc, swapped the vga driver, the MB, I made over to 3.4GHz and still is a waste.
I can not identify where the problem is, I'm very discouraged.
And another is not so bad is that the BFBC2, other games are also not here with performance that I wanted with this VGA.
Resident Evil 5 average of 71fps, and 90fps reviews showed average.
Street Fighter 5 averages 84fps, over 100fps show reviews
Mafia II medium without pshyx 40fps, 50fps reviews were.

My specs ..
EVGA 780i SLI MB (with latest BIOS)
Ram 4gb Gskill 1000MHz
Seveteam 620pa f-620W
Windows 7 Ultimate 64bit

Someone who has gone through a problem so help me!  

Sorry for my English confusing, in my country do not speak it so I used Google translator.  

Thank you.