All this "30fps is not enough talk" needs some serious blind testing imho.
There are a lot of approaches to deal with your question, but probably most telling would be apply a scenario where "X is not enough" and challenge the basis--and see people's response. Or turn it into a challenge statement:
UC2 graphics are enough.
Crysis graphics are enough.
2 button controllers are enough.
One racing sim is enough.
5 guns is enough.
One FPS game is enough.
In the end market demand determines what is enough--even if market segments can see the difference.
Where the rubber meets the road is when the primary audiance (e.g. racing fans) demand a feature (e.g. 60Hz) because they do not and anything less
is not enough.
Whether 60Hz is noticable isn't really debatable, the questions are is it distinct enough to most consumers? A selling point? Make the game better? Lack thereof make the game unplayable? A good tradeoff for other features?
Would Gears 2 be a better game at 60Hz with cut down graphics, AI, etc? Probably not. On the other hand Forza 3 would be less compelling to its core demographic at 30Hz.
Billy Idol - Banned
Obonicus - Banned
Mike Acton - He's banned. Twice!
...I imagine the findings are most people can't perceive the difference.
About time! No mercy for those heathens! Now if you can have the same approach to the baiters, trollers, and obstinant you will get Mod of the Year
As for 60Hz, I agree, I bet most cannot notice.
Of course a lot of people don't notice the finer points of gameplay, either. I think a very strong core really set the tone for a lot of games and that there is a huge disconnect between the casual "that was so cool" market and the "I want every inch of gameplay world to be perfectly mapped for optimal competitive carnage!"
Btw, this is why the B3D Live group rocks--we actually discuss game design, technology, and all the bad posts here during gameplay
In terms of processing resources (assuming a single developement platform) how much processing resources would a drop from 60fps to 30fps free up?
Rachet & Clank games look amazing enough to me that I thought they were indeed 30fps games. If they can free up significant resource for adding lots more visual "pop" then why not?
Carmack noted Doom 4 would look ~3 times better than Rage based on the general larger margine 30Hz gives you. Lets say you need to target 75fps +/- 15fps to have a stable 60Hz game. At 30Hz since you are rendering half as often you can lower some of your tolerance (what was once, e.g., a 2ms window for a task now becomes 4ms, and you also can lower some of your tolerances).
Like homerdog said, I think people may notice which looks better. Enough to influence sales? AFAIK Acton isn't saying that 60fps isn't superior to 30fps, it's just that 60fps isn't a selling point. It's not going to push anyone to buy the game.
With rare exception (racing sims--although NF Shi
ft vs. FM3 sales will be interesting!!) I don't think sales are hugely impacted and reviewers and their scores (gameplay, graphics) are impacted much by framerate and it isn't something that can be spotted in a) magazine pics b) box art c) online pics d) most gameplay video feeds so on and so forth.
In most cases better still graphics has more impact.