Low Fps in CS:Source with EVGA GT 430

hy guyz!!!
i recently bought EVGA GT 430( 1GB DDR 3) and im getting 60-130 fps online in counter strike source, i have the latest drivers!!!
i was getting same fps shown above with NVIDIA 9400 GT (512 MB),
so tell me whats the purpose of this 1 GB card (DDR3) if its not have the power of increasing the fps ?