I'm not really... at my last sentence I did make this clear ("*if* such a chip exists"). Traditionally though nVidia has in the works a big chip and in this generation this doesn't seem to be the case. Either they had problems on developing that (big) chip, or they changed their strategy (focusing only on medium chips), OR they hold their product away from the marker purposefully. Since I'm not an insider I cannot know which of those is the truth, what I do know (assume in fact) is that if they indeed hold their product from the market (*if* they do that) then it's a damn shame which may even affect them negatively in the long term (the 8800GTX affair made nVidia queen of sales for that 2-3 years period following that release, if history has taught us something is that if you have a strong lead on the market you better show it)...
Anyhow like I said I don't know and I cannot know for sure, traditionally though the even numbers on nVidia's counting system (GF 4xx, GF6xxx, GF 8xxx, GTX 2xx, etc) were denoting an overhaul in architecture and an almost 100% increase in performance compared to the last (even) generation. While the odd numbers were denoting smaller changes (a bit like Intel's tick). This generation around, that symmetry appears to have been broken (which is also what lead me to believe that nVidia actually do/did have a big chip on the works).
Bookmarks