Sorry, just a noobie question here. hope i don't get flamed i was wondering, does the 128 bit memory of the 8500 and 8600 series become a bottleneck to the GC's performance?

i'am currently using a 6800GS with 512 MB 256 bit memory and i performs sweetly. i was thinking of an upgrade to GF8 series but 8800 series seems out of my budget range.