As I said before, some time ago, I do not play in +12 pixel rate (the recommended setting) or else my laptop crashes by overheating.
However, it was never a problem to grow crops or smelt objects. In fact I used to take long trips from farm to farm in order to get lots of wheat and whatnot. Lately, for some strange reason, the crops are taking forever to grow, if I can even call that. Besides the painfully slow cicle, it's also a very rare occurrence to see all the crops 100% ready, usually getting stuck on 60% or less. It gets weirder considering every "farmable" object is behaving like that, and not only wheat.
Things like sugar cane and potatoes, who used to grew ridiculously quick, are getting stuck for 5 or 6 days (yes i counted) in the exactly same stage.
And I really mean EVERY farmable object. Trees are also taking forever, not only to grow, but also to drop objects and disappear.
Needless to say that playing is getting less and less fun by the day for obvious reasons. It's something to do with my settings? If the answer is "yes", why it was never a issue before?
Also, smelting objects is now only working if I stay paralyzed looking at the furnace until the work is done, or else it will stuck in time until I come back near the furnace. Going just a little far away is enough to freeze the process.
What the hell is happening? Is something to do with the new composter mechanisms, or just the game not loading properly? Maybe I turned off something important on OptiFine?
However the reason is, the game is now basically broken. It's impossible to progress at Minecraft without functioning farms.
Sounds just like you're going out of render distance. Maybe before you were just in render distance whilst doing other things. Id just make a farming area with automated farms. Then just afk there occasionally. Farming by hand is just too much of a chore anyway.