If im in main world with 2 or 3 players, i get 20TPS, like absolutely no lag at all. When i go to the nether, TPS drops to 10 or under, lag spikes occur and stuff like that. Why does this do this an can this be fixed? Bump EDIT by Moderator: merged posts, please use the edit button instead of double posting.
What's TPS supposed to mean? Tweets per second? If you mean FPS and your client, it's most probably the (flowing) lava down there.
Haha. Well, assuming it's not some prank someone played on him, like spawning a huge amount of items down there, the huge amounts of lava and the nether mob would still be my best guess, since they do affect the server load as well.
Flowing lava (and water) do cause lag. Oceans are still water. What happens when you disable mob? If you get such serious lag with 2 or 3 players, your computer may just not be fit to be run as a server. However, to my knowledge, having players in the Nether is almost always more CPU intensive than having them on a normal or skylands map.
I get the same in 1.2 current, I would guess it is the lava, and I am getting lag from internal i.p connection on the same network, so it is the world for sure, I would advise you either mass remove flowing lava or try to limit mob spawning in the nether.
Could it possibly also have to do with the lighting generated by the flowing lava? Is there a way, with the plugin api, to block light-generation from flowing lava?
Try to remove all drops in nether, they affects on client and server performance. While nether world is empty, chunks are not loaded, and server do not process items in that chunks. Once you enter nether world, chunks is loaded and server (and client too) start lagging
