Onus :
I'd like to see a tier shaded on the hierarchy chart, below which modern games would be considered unplayable (below 30FPS on "low" settings). For example, a couple years ago, an Athlon II X2 260 could still play any game on "decent" settings, but I'm not sure that's true any more. So, where is the cutoff?
well the problem with that is everyone likes differnet quality of settings. Some like maxing everything out which i can still do with most games of mine on steam with only an i5-3330 with a GT 620. Now of course i cant even get close to doing that without a ton of jerking animations in Watch_Dogs, Shadow of Mordor, AC: Unity, and etc.
Acceptable frame rates also depend on the amount of action on the screen for example the game of " The Crew " can probably get away with a fps of 40~45 and still look very smooth becuase of what kind of game it is but a game of Shadow of Mordor wont feel nor look that good below 60 fps becuase of how interactive and reactive the combat system in it is.
So for MINIMUM FRAME PER SECOND RATES these are what i think:
for raceing games 30 fps with low or medium settings doesnt ussualy look that diffenret from 60 fps with high or Ultra settings ... of course " The Crew " is the out lier where it does as Ubisoft really detailed everything even what didnt need to be. " The Crew " is still smooth at 40~45fps during the high speed chases and smooth at 30~40 fps when not doing the high speed chases though if not doing them and your fps is that low then your screwed at the point that they do happen.
for action games it is ussualy around 40~60 fps depending on how reactive the game is and the graphics quailty settings ussualy turning on shadows helps with some of the unussual darknesses and unussual brightness spots in the game otherwise medium is usssualy good for a minimum.
for turn based RPGs around 10~20 fps during combat is acceptable and 20~30 fps during the time of running around the open world with the settings staying static so choose one and stick with it.
for real time based 30~40 fps during the entire game both for combat and running aroud in the open world. Just because it is a real time based combat system and if you are not running you are ussualy being hit by the enemy.
for turn based stragey games around 5~10 fps is a good minimum higher is nice but not needed as long as everything is static but if it is moveing then 24~30 fps so the animations look smooth.
for RTS games 10~20 fps but a static fps is going to be best for RTS games so the ones which allow you to lock it that is the best solution. higher is better for larger maps but 10~20 fps is good for small to medium sized maps with it zoomed out enough for you to see all your units and base(s) if possiable anyways.
It is always good to note that higher almost always equals better to a point that higher is not really giveing you anything much more to see. This is true in all the real time based games be it Action, Adventure, RPG or RTS games but higher is ussualy not needed in turn based ones which you can just turn it up to max quailty and still have a good gaming time in them.