Simulation Lag Fix

This is an update to simmythesim's Simulation Lag Fix for the latest version of the game.
It was also previously maintained by Xerox on Mod The Sims, but they no longer are keeping it updated.

I have been updating the mod for quite some time now via the comments on Xerox's MTS page. But decided I should post it here so I do not forget to update it in the future.

I have not changed anything from the original mod, I simply just updated the python code and patched it for the most recent update for The Sims 4.

What does this mod do?

"This mod alters the game's simulation so that sim autonomy does not cause massive simulation lag in instances where there are many autonomy requests."

This should eliminate, or at the very least, alleviate, the following problems:

  • Sims head bobbing
  • Sims doing nothing for a few hours
  • time slowing down on speed 3
  • time going back to the past

Mod Explanation

This seems rather basic, but there's a video showing a scientist experimenting in GTW without the mod:

Here it is with the mod installed:

Everything runs much more frequently now, preventing the "bobbing head" effect. I haven't experienced any time rolling-back since I made the mod!


This mod overrides the following python functions:

  • time_service.TimeService.start
  • time_service.TimeService.update


Unzip the mod files into your mods folder.
Make sure script mods and custom content are enabled in your game!

Additional Credits:

simmythesim for the original mod & page description


NOTE: If you have any issues with this mod, or want to report any bugs please do so in Discord under the #bug_reports section. This is the best way to get quick and easy 1 on 1 help. 


  1. I am so glad you have taken over love this mon

  2. Thank you! You are a saint!! My game is unplayable without this mod

  3. I'm so happy this mod exists! ♥

  4. There are many of us who are so very appreciative of your work and efforts to make the Sims 4 more playable. Thanks so much!

  5. Hi, I appreciate this mod so much, thank you for updating it! Love from Germany.

  6. Thank you so much for fixing and sharing this!

  7. Love how you keep this up to date, noticed an update just today :D

  8. Thanks for keeping this up to date

  9. Hail!
    One quick question, does this mod do the same as the Simulation Unclogger from Turbodriver, or they adress different problems, and would be usefull to be used together.

    1. Good question! The answer is yes, they do two different things and are compatible with each other.

  10. Love your mods, and keep up the good work.

  11. Can this mod be used with MCC? I have mcc adjusting game time speed so thought it was worth asking.

    1. If you adjust game time speed with MCCC this will not work. You would have to pick which mod you want to adjust game speed. This mod does however adjust time differently then MCCC.