Description
Sofwyn Simulation Fix is a technical performance mod designed to significantly improve simulation smoothness and responsiveness in The Sims 4, especially in heavily populated or long-running saves.
Please note that this mod is not compatible with Simulation Unclogger by TURBODRIVER, Simulation Lag Fix by SrslySims or coolspear’s mod, as they all overlap with features already included in this mod.
This mod has been updated on April 26, 2026.
The main issue found was the missing return value in patchedupdate — the original TimeService.update() result was being discarded instead of returned.
Key Features
Smart Time Budget Management
Caps simulation time at 17 ms per frame, with an optimized allocation: 62% dedicated to player-controlled Sims and 38% to NPCs. This ensures responsiveness where it matters most.
Enhanced Prioritization of Playable Sims
Your Sims react faster to interactions, even in direct control mode or within large households.
Active Autonomy Queue Management
Includes automatic draining and cleanup of the autonomy queue every 45 seconds, preventing the buildup of outdated or redundant requests.
Improved Long-Term Stability
Designed to maintain consistent performance in demanding saves, reducing slowdowns over time.
Modern Optimization Approach
Refines simulation performance without disrupting the natural pacing or behavior of the game.
📁 Installation: Place this mod directly in the root of your Mods folder (do not put it in any subfolders). Remove any other simulation fix mods before using this one to avoid conflicts.
⚠️ Clearing your cache is necessary for the mod to work properly.
⚠️ Requirement: This mod is base game compatible and does not require any DLC to function.
🐞 Note: As with any mod, unexpected bugs or conflicts may occur depending on your setup. If you encounter any issues, feel free to report them in the comments so they can be investigated and fixed in future updates.
You can also find more of my mods on Patreon: https://www.patreon.com/cw/sofwyn