In my singleplayer world there are at least 5 chunks near my spawnchunks that create a lag spike when I cross in a certain direction. I RECREATED THIS ISSUE IN VANILLA, WITH NO OPTIFINE, NO RESOURCE PACKS, NO MODS, NO NOTHING. I REPEAT, THIS ISSUE IS NOT FROM A RESOURCE PACK, OR A MOD, IS IN VANILLA. Here is a video of an example of what is happening in my world. THIS VIDEO IS NOT OF MY SURVIVAL WORLD. BUT THE PROBLEM IS THE SAME: https://www.youtube.com/watch?v=3-rpttcUIm4