FixMySpawnR
Modby AbsolemJackdaw
fixes lag induced by active but unused spawners
Downloads
6,368,948
Type
Mod
CurseForge ID
626476
Last Updated
Apr 9, 2026
Description
Fix My SpawnR !
FixMySpawnR Claims to reduce about half of the tps lag caused by mobspawners.
A bunch of mods add dungeons and caves and fun stuff with mobspawners in them, but mobspawners are pretty heavy on server logic. they scan a big area for players and for spots to spawn mobs in. if players load these spawners in the chunks they are in, the server can quickly suffer unnecessary additional strain per tps
This mod aims to fix that.
What Does FixMySpawnR do ?
FixMySpawnR adds a deadlock timer to mobspawners that will prevent them from running any spawning logic, and thus preventing all that precious computing space to be freed for other logics to run on !
What about farms ??
1.18
If a redstone signal is placed on top of the spawner , higher or equal to 8, (powered redstone dust, redstone torch, redstone block, ...) then the spawner will resume function as normal.
The recommended way is redstone dust and a lever. this emits the least ammount of light
1.19
If a redstone signal is driven into the spawner, higher or equal to 8, then the spawner will resume function as normal. This includes torch bellow the spawner, a lever on the side of the spawner, etc.
The spawner will resume function as normal when powered.
The recommended way is a lever, as this will produce 0 light, and occupy the least space
This way, players can still use their favourite mob farms to automate their hoarding needs.
Configuration ?
The mod is server side only. connecting clients do no need this mod. (note, this mod also helps in single player worlds, but it wont probably be as effective in lag reduction as on big servers)
You can configure the deadlock timer in the server sided configuration file.
The base timer is 1 in game minecraft day (24000 ticks)
Does it really work ?
Here's a picture of TPS and ms per tick from a server tested with one player in.
A cube of 40*10*40 spawners (thats 16.000 spawners) has been spawned in the same tick.
You can clearly see here the exact moment all spawners get deactivated at once.

Before (no deadlock, 16.000 spawners)
After (deadlocked kicked in, 16.000 spawners)
The mod reduces the tickload by half , dropping the average millisecond a tick takes to run from 20 to 10 (19to8) and the max from 50 to 15 (48to13)
While it reduces but a small strain, it definitely will bare its fruit in the long game, for packs and servers that add mods with structures containing spawners.
contact :
for issues, please use the issue tracker linked on top.
if you want to speak to me directly for debugging 1-0-1 with the mod, or questions, feel free to join my discord
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