Nvidia's GeForce 8800-series graphics cards have generously wide memory buses, but their upcoming mainstream siblings may end up being a little more bandwidth-constrained. According to a report by VR-Zone, GeForce 8600 cards will have 128-bit-wide memory buses, just like their GeForce 7600- and GeForce 6600-series predecessors.The site says Nvidia will introduce two GeForce 8600 models: a GeForce 8600 GT with a 650MHz core clock and 900MHz memory and a GeForce 8600 GS with 550MHz core and 700MHz memory clocks. Both models will have 64 stream processors, a 128-bit memory bus, and 256MB of GDDR3 RAM. Those specs contradict previous rumors, and they suggest the two cards will only have 28.8GB/s and 22.4GB/s of memory bandwidth—pretty low considering the GeForce 7900 GS has 42.2GB/s.
Not as as we'd like it , probably only twice as fast as the 7600gt and just matching the 7900gt /x1900gt , but with DX10 . Still very good value for money , but 8800 will be twice as fast, and may be better bang for buck if you can get a lower end model for like 250 and unlock pipelines .