AMD64x2 6400+BE or AMD Quad 9850 BE?

I have an Asus m2n-sli deluxe board and it is limited to a amd9850 quad. I presently have an amd64x2 6400+ BE

I mostly game. Will I see an increase in performance buying the quad 9850 or should I stay with the 64x2 6400+ BE.

My prestent specs are as follows:
AMD 64x2 6400+ BE
Asus M2n-sli deluxe mobo
2 x evga 8800gtx in sli
Vista 64bit
(8) gig (4x2gig) XMS2 memory

 

if you play newer games that will take advantage of all 4 cores, then yes, you will see an improvement.

 

get a new mobo and get a core i7, those things are screaming fast! and soooooooo easy to overclock, i had mine up to 3.6ghz stable but i turned it back to factory because i saw no point in having it overclocked as i did not see much of a increase in speed cuz thing has eight logical cores!