When i'm trying to enter any world i can see a loading screen, but when it finish no one chunks are loaded. And i don't know why this happen, and this is a problem of any Minecraft versión ¿Why i see a loading screen and game is no loading when finish the loading screen?
In addition, the game "is working" when Chunks are loading, and mobs spawn and aproch to me and hit me, but game is loading, fps are low and don't know whats is loading few moments ago in loading screen.

¿Why game is loading previuos and after loading screen screen? ¿It whould no must do a real loading?

I no understand that.

PD: I know, in a pc gaming this no happen, but there're folks without money to buy it. And i have no a bad pc, 3GB Ram are enough to play minecraft or i must to assing more ram? (i have 8GB avalible