Any new driver(kext) for nVidia 9500GT 1GB card for OS X 10.6.4?

[ajaylion2]

i'm experiencing laggish gameplay in assassin's creed 2 on my mac pc. but AC2 runs well in my latest updated driver in windows. while installation i remember i checked only NVenabler. Plz any suggestions? i'm a newbie to mac. My specs are:
Intel Quad Core Q8300 2.5ghz
3gig Ram
Intel DG45ID mobo
nVidia 9500GT Zotac 1gb card
solutions would be grateful!thnx