The GeForce 6600 GT cannot compete with it nor can the GeForce 6800 GT. Yes, the GeForce 6800 GT can stay within range, performance-wise, but when you consider the higher price of the GeForce 6800 GT and compare the attributes of the GeForce 6800 GS, in both price and performance, it's a no-brainer. For those budget-minded gamers who are considering an upgrade to PCI-E this card should be on your short-list for consideration.

Going with two GeForce 6800 GS cards in SLI is another matter and I hesitate to recommend taking this path. One GeForce 6800 GS, like the XFX GeForce 6800 GS XXX Edition, will provide enjoyable gaming performance in the latest games, albeit at moderate resolutions, with use of antialiasing. Going with two cards in SLI will allow use of 4xAA at moderate resolutions but at double the expense. This is the touchy point as paying $400 for the two cards is more than you would pay for a GeForce 7800 GT and almost the price of a GeForce 7800 GTX. I would strongly consider either of these cards as a single card solution over the 6800 GS in an SLI configuration.