Need Help with FFXIV Configuration

[Anima]

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.

On FPS Limit 30, I use:
Multi-sampling: 4xMSAA
General Drawing: 8
Background Drawing: 4
Shadow Detail: High-Highest
Ambient Occlusion: None
Depth of Field: None
Texture Quality: High
Texture Filtering: Highest

AMD Setting:
Anti-aliasing: 4x
Anisotropic Filtering: 8x
Tesselation: 64x
Texture Filtering: Quality
AA Mode: Adaptive MSAA

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.

A few questions, What is the difference between 60FPS Cap and 30FPS cap ? Is it beneficial for me to change Cap to 60 whilst lowering some of my configs ?
I want the game to look great/decent while running smooth in all cases >.>
(Searched about FPS but couldn't find any hints, I know that's Its Frames per second / Frame rate)

-Thank you

P.S.
If I'm staying for 30 FPS Cap I can raise my config a little, If It's 60 FPS Cap I've to lower some of my config quite a bit.

[Onisake]

Why do you need 60 FPS? your eyes aren't capable of really enjoying the added frame rates above 30 anyway.

Your GPU doesn't have a limiter. if you cap it at 30, it won't try to render anything above that. by setting cap to 60, you will be trying to render at 60, there's nothing telling your processors to stop so it will just push itself to the limit. consequently this bogs down your system and causes the frames to drop. the graphics engine is not optimized, remember.

If you're running fine at 30, leave it at 30.

[Eekiki]

Why do you need 60 FPS? your eyes aren't capable of really enjoying the added frame rates above 30 anyway

This is not true at all. If you aren't seeing a difference between 30 and 60 fps, either your computer is too slow to do more than 30fps anyway, or there's something wrong with your eyes.