[MC-2932] Spawn chunks are loaded all the time even in singleplayer

From some tests I did it looks like a few chunks around the spawn are constantly loaded.
Probably it's a legacy from the multi/single player merge. But I don't see a reason why there should be chunks loaded all the time if no player is around. If there is one please let me know.

I guess it causes the game to use a little bit more memory than necessary.

Also the entities in this area are loaded and interfer with the mobspawning. For hostile mobs that's no problem because they despawn anyways if no player is in a 128 radius. But if there are a few peaceful creatures close to the spawn the peaceful mobspawning does not work in any place in this world because of the mobcap.

I hope you understand why I think that it is a bug and just in case works as intended I would like to know why.

Linked issues

is duplicated by 1

MC-23085 Chunks near spawn don't unload Resolved

relates to 1

MC-42270 Unable to /setblock or /summon to new world spawn point Resolved

Comments 16

Joël Fivat 2012-11-14T08:28:40Z

I have to remember to make a crop farm there then.

Btw, how do you know it is always loaded in memory ?

Joël Fivat 2012-11-14T08:40:45Z

Also, what do you mean by "peaceful mob spawning" ? In my understanding the animals are now persistent, they are only created when the chunk is created and there is no cap for them (I have hundreds of animals in my farm but I can still find wild ones just outside).

Mustek 2012-11-14T12:33:00Z

If I remember correctly, those chunks are always loaded as to prevent falling through the void when you respawn.
I'm going to leave this open for a Mojangsta to comment on though, as I'm not sure.

Panda4994 2012-11-14T12:56:57Z

@Joël Fivat
I'm not sure but I think the random update ticks which are needed for crop farms are not processed in this area.

I know that it is always loaded because I spawned a few chicken there and teleported 10000 blocks away. When I came back after 5 minutes the chicken have laid eggs.

There are two ways peaceful mobs can spawn (as far as I know):
1. On the world generation
2. Randomly like hostile mobs (not as often) if the mob cap is not reached (which doesn't work because of this bug)

@Mustek
Thank you for leaving it open. If I remember right they fixed the falling into the void bug in an other way now. So there is no need for that anymore. (Also you respawn at the bed you last slept in)

Tails 2013-03-15T17:55:41Z

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

6 more comments

Haz 2013-04-26T14:17:44Z

this is not a bug but a feature

Panda4994 2013-05-10T15:54:39Z

@Tails
I can't confirm it for the current version (1.5.2). I guess it's not a concern anymore.

Tails 2013-05-10T16:42:32Z

Actually was able to confirm in 13w19a. Build an End portal at original spawn and let a piston drop sand from a sand tower into it. Go to the End and observe sand spawning eventhough the chunks should not be loaded since noone is in the overworld.

Greg Garcia 2013-06-03T10:24:16Z

A 12x12 chunk area at spawn always stays loaded in single player, there are numerous player designed iron farms, mob farms, chicken farms, etc. that take advantage of this fact. It is a fairly well known function of the game and is seen as a feature and not as a bug. Numerous Youtube videos exist explaining how to determine the exact area included in your "spawn chunks" and how best to use them.

As far as the reporter of this issues concerns about animals (passive mobs) there eliminating spawning elsewhere in his world they are invalid. Passive mobs have a spawn cap of 11, once every 20 seconds the game checks in a 17x17 chunk area with the player at the center to count the number of passive mobs.

If there are less than 11 passive mobs within that range then more can spawn, no closer than 24 blocks from the player and no further away than 128 blocks. They can only spawn on grass lit to light level 11 or higher (even mooshrooms, which is a bug btw, they should be able to spawn on mycelium).

The point being that animals within the "spawn chunks" have absolutely no effect on spawning elsewhere in the world. The spawn cap is not for the world itself, it is only for the 17x17 chunk area currently surrounding the player.

Moo 2013-08-28T22:20:28Z

^ is incorrect. The cap is per-world. See http://www.minecraftwiki.net/wiki/Spawn#Mob_spawning. Animals in any loaded chunk would count against this limit.
Also, that the spawn chunks always being loaded is well known and utilised by people doesn't mean it's sensible or intended.
IMHO the spawn chunks remaining loaded only makes sense on a true multiplayer server, where quick load times for new players would be an advantage. On single player where you're likely to be off somewhere far from "spawn" (if not taking advantage of the spawn-loaded-chunks, anyway), it doesn't seem to have a purpose, and is probably just byproduct of the internal-server system.

Anon Ymus 2013-08-30T01:11:28Z

That information is for hostile mob spawning, not friendly mob spawning.

Moo 2013-08-30T10:23:29Z

No, it's for both. There's a separate cap for hostiles and friendlies, but the cap still works the same way. Just like having enough hostiles loaded in a mob farm prevents hostiles generating anywhere else, having enough animals loaded in an animal farm prevents them spawning anywhere else. And the cap for animals is lower to begin with.

CubeTheThird 2013-09-26T04:34:08Z

Is this still a concern in the current Minecraft version 1.6.4 / Launcher version 1.2.5 ? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

Keybounce 2013-10-21T15:48:16Z

Yes, this is still an issue in the current version, with the current launcher, or the current multiplayer server, or the current single player game.

Seriously Dinnerbones, you said this is indended? Can you please explain why you consider this a desirable or intended feature? Yes, you can load command blocks and redstone near spawn and they will always work – how many of us actually use that? Can you at least give us server control of the loaded radius as a compromise?

Maarten Thijs 2013-10-21T16:25:19Z

your iron farm will allways work. how awsome is that?

Moo 2013-10-23T14:50:16Z

Yes, a rationale for it being an intended feature would help...
Hopefully the new /setworldspawn command changes the area that is kept loaded, allowing it to be moved to a location that is helpful, or at least less unhelpful...