Here is a question posted from a player who did not know the difference between capping at 30 fps vs 60 fps. He stated an interesting observation.

Quote Originally Posted by Anima View Post
So I'm actually not a new player, but I feels weird to post "Config" question in General Discussion so I'm gonna ask here.

I'm playing FFXIV in an average Config, but I'm playing on Limit FPS 30.

...

I have no problems, no lags, all smooth with these config, but once I change Cap to 60 FPS the game Lags when there's a lot of objects to load, and especially on Raining, Sandstorm, CS, etc.
This is the same effect people experience when they enter a crowded area like Ul'dah. The brain exaggerates a drop of 60 fps to 25 fps as a decrease of responsiveness than one of 30 fps to 25 fps. The reason of course is that you subconsciously adjust your response to the rate at which you interpret changes in visual information. In other words, a consistent FPS appears more fluid than a constantly fluctuating one.

From a developer perspective, your goal is to keep the frame rate about 20% within the target fps. If you exceed that 20%, you either need to tweak the environment so to get the frame rate up, or lower the target fps. And since the game developers of this game want higher detail by sacrificing frame rate, the cap should be set at 30. As time passes and hardware improves, environments within the game will become more complex, but the frame rate need not change.

60 FPS or above would require keeping the game frame rate above the mid 40s. And few players can achieve that. Maybe a small few will be able to, but you are in the minority and the majority comes first.