Well, considering the power of two 6800gt's at 512mb and that, two 6800gt's would be a more powerful solution to a 7800gtx, but, if you really break it down, they're almost the same. But two 6800gt's, from the benchmark's I've seen would offer a little more of an increase in performance. Why? Because the clock's of the 6800gt are like, what, 420mhz, and the 7800gtzx was around 425mhz, so not much, and with dual's the performance is seen....