The Sims 4 looks smooth at 60 FPS, then your Sims just stop. The camera still pans fine. Ambient animations still play. But actions sit in the queue, the clock freezes, and clicking a fridge takes 5 to 10 seconds to open the pie menu. That is not a normal FPS drops problem. That is Simulation Lag, where the game logic cannot finish its simulation tick on time.
This guide shows how to fix Sims 4 lag on PC, including stuck Sims, time jumps, and pie menu delay. You will learn the fastest “start here” fixes (cloud sync conflicts, cache corruption, save bloat), plus the same system hygiene principles used to fix PC stuttering in games and overall computer lag.
Fix Sims 4 Simulation Lag: Start Here
Most “lagging in simulation” comes from three specific issues you can fix in under 10 minutes.
Critical Fixes For Sims 4 Simulation Lag
Do these in order. Each step targets the most common causes of “Lagging In Simulation” and fixes the stuck Sim timeline without guesswork.
Disable OneDrive Sync For The Sims 4 Folder
If your Documents folder is backed up to OneDrive, The Sims 4 can freeze whenever it writes saves, caches, or thumbnails. Cloud sync is a known cause of “freeze and catch up” behavior in many games, similar to the mechanics explained in why you get lag spikes. Stop syncing Documents\Electronic Arts\The Sims 4 and keep it on a local drive.
Delete localthumbcache.package Every Session
This cache stores more than thumbnails. It can keep stale tuning data from removed Mods and CC. Deleting it forces a clean rebuild and removes a common source of simulation hiccups and frame time stutter.
Run The New Save Test To Isolate The Cause
Rename your Sims 4 folder so the game generates a fresh vanilla folder. If lag disappears, your old save or Mods folder is the problem. This test prevents hours of random tweaking, just like a clean baseline test used in system lag troubleshooting.
Close Overlays And Set TS4_x64.exe High Priority
The Sims 4 simulation logic runs primarily on one CPU core. If overlays and background apps interrupt that core, simulation stalls. This is the same root cause described in PC stuttering diagnostics and Windows gaming optimization.
Simulation Lag: camera is smooth, but Sims freeze, queued actions do not start, the clock stops then jumps forward, and the pie menu opens late. This is the logic engine falling behind.
If your problem is “Sims stand still for hours,” you are fixing simulation, not graphics.
Turn “Lag” Into A Real Root Cause.
If your whole system feels slow outside Sims 4, start with speeding up your PC, then apply game-specific fixes. Stable Windows equals stable simulation.
Diagnose Sims 4 Simulation Lag In 60 Seconds
Before you change settings, confirm you are dealing with simulation latency. These quick checks tell you which layer is failing: graphics, logic, files, or mods.
Quick Simulation Lag Test
Do these checks in live gameplay, not on the main menu
Fix Sims 4 Lag By Disabling OneDrive And Cloud Sync
If your Sims 4 user folder is inside a synced Documents directory, you can get random freezes during saving, traveling, and thumbnail updates. Cloud apps can lock files while uploading, and the game waits. That wait stalls the simulation thread and looks like “everything is stuck.” If you also see internet spikes, review how to fix ping spikes and make sure sync apps are not saturating upload.
Cloud Sync Remediation Workflow
Stop file locks by keeping The Sims 4 folder local
Documents\Electronic Arts\The Sims 4. If you see OneDrive\Documents in the path, it is being synced.The Sims 4 folder back to local Documents (not OneDrive). Keep Saves, Tray, and Mods intact during the move.Clear Sims 4 Cache Files To Stop Simulation Lag
Cache bloat and corruption is a top-tier cause of simulation hitching, especially if you add and remove Mods or CC. The most important file is localthumbcache.package. Delete it first. If your symptoms look like micro-freezes and catch-up behavior, that is the same “frame time problem” described in PC stuttering and FPS drops troubleshooting.
Sims 4 Cache Files You Can Delete Safely
| File Or Folder | What It Affects | When To Delete | Impact |
|---|---|---|---|
| localthumbcache.package | Cached tuning, thumbnails, stale references to removed Mods and CC | Before every session if you use Mods or CC | High |
| localsimtexturecache.package | CAS composited Sim textures; can bloat and cause delays | If CAS is slow, Sim thumbnails glitch, or after large CC changes | Medium |
| avatarcache.package | Gallery and Sim profile cache | If Gallery UI is slow or after big patch updates | Low |
| cache folder | General temporary cache | When troubleshooting persistent lag or after patches | Medium |
| cachestr folder | String cache used for assets and UI | If UI is delayed, pie menu hangs, or after content removal | Medium |
| onlinethumbnailcache folder | Online thumbnails (Gallery) | If Gallery browsing is sluggish | Low |
Cache Clearing Workflow
Fast, safe, and repeatable
Documents\Electronic Arts\The Sims 4\ and delete localthumbcache.package.Fix Sims 4 Save Lag With Save As Rotation
Long-running saves accumulate bloat: deleted objects, outdated interaction state, broken event scripts, and oversized household inventories. Using Save As builds a fresh container and can reduce internal fragmentation that contributes to simulation stalls. This is the same “keep things clean and repeatable” idea behind speeding up a slow PC.
Save As Protocol For Simulation Lag
A simple routine that prevents save entropy
Legacy_A, Legacy_B, Legacy_C.Reduce Sims 4 Lag From Inventory And Household Bloat
Inventories are not just lists. They are active databases the game indexes constantly to decide which interactions are valid. If your household inventory has thousands of items, the game pauses when it needs to query or sort them. This is a Sims-specific version of the “too many background tasks” concept in game lagging on PC.
- Sell excess harvestables instead of hoarding hundreds of unique items
- Move collectibles to display shelves or storage lots, not pockets
- Delete or sell duplicated books and upgrade parts
- Keep “daily carry” inventory lean: aim for fewer than 50 items
- Enter Build Mode and open Household Inventory
- Sell duplicates and remove unwanted debug items
- Avoid storing huge stacks of crafted items and collectibles here
- Keep the active lot focused: store extras on a “warehouse” lot if needed
- Avoid settings that balloon the world to thousands of Sims
- Do not raise “max Sims on lot” above the default unless you accept lag
- Keep unplayed relationship networks clean to reduce social calculations
- If your save is ancient, use Save As rotation more often
Set TS4_x64.exe High Priority To Reduce Sims 4 Lag
The Sims 4 simulation is sensitive to interruptions because its core logic is largely single-threaded. If Windows background tasks or overlays steal CPU time, the logic tick misses deadlines and the game “lags in simulation.” If you have not already, do the general base layer first: optimize Windows for gaming and review how to reduce lag on PC.
- Disable Discord overlay
- Disable Steam overlay (if you play on Steam)
- Disable GeForce Experience / AMD overlay
- Turn off Xbox Game Bar if it hooks games on your PC
- Exit MSI Afterburner and similar monitoring tools
- Close iCUE, Razer Synapse, NZXT CAM, and similar suites
- Close browser tabs and background launchers you do not need
- If needed, use the same “clean baseline” approach described in fixing computer lag
- Use a performance power plan while playing
- Ensure your laptop is plugged in
- Check CPU temperatures if lag worsens over time
- If your whole PC slows down, follow how to speed up your PC first
DirectX 11 Vs DirectX 9 For Sims 4 Performance
DirectX mode can change rendering performance, but simulation lag is primarily logic-based. Still, if your system is unstable in one mode, switching can improve overall smoothness. Benchmark both modes and keep the one that is stable on your hardware. If you are tuning visuals to reduce perceived input delay, review what VSync is and why it often adds latency.
Advanced Sims 4 Simulation Lag Diagnostics
If you still get simulation lag after cloud sync fixes and cache clearing, stop guessing. Run these two diagnostics. They tell you if the issue is system-level or caused by your save or mods. If your baseline test still feels slow everywhere, start with fixing computer lag and optimizing your PC for gaming.
The New Save Test
The fastest binary test for Sims 4 simulation lag
Documents\Electronic Arts\ and rename The Sims 4 to The Sims 4_Backup.The Sims 4 folder automatically.LastException Workflow
Find the script or object that is stalling the simulation
Documents\Electronic Arts\The Sims 4\, look for LastException.txt after a lag spike.Conclusion
To fix Sims 4 lagging in simulation, focus on the logic pipeline: disable OneDrive and other cloud sync file locks, delete localthumbcache.package regularly, and use the New Save Test to isolate whether the cause is system-level or save and mods. Reduce inventory bloat, simplify routing-heavy builds, and do not overload the simulation with extreme zone populations. If your PC is generally unstable, fix the base first with Windows gaming optimization and PC optimization. Done right, Sims respond instantly again, the clock stays accurate, and the pie menu becomes snappy.
FAQ
What is Sims 4 Simulation Lag
Simulation lag is when The Sims 4 logic engine cannot process the simulation tick on time. The camera and animations may remain smooth, but Sims freeze, actions stay queued, time stops then jumps forward, and the pie menu opens late.
Why does Sims 4 lag in simulation but FPS is fine
FPS is graphics. Simulation is logic. The Sims 4 can render smoothly while the single simulation thread is clogged by save bloat, heavy inventories, routing complexity, or script-heavy mods. Background apps and cloud sync file locks can also stall the logic thread. If you suspect general PC issues, start with fixing computer lag.
How do I fix Sims 4 pie menu delay
Delete localthumbcache.package and clear cache folders if needed. Disable OneDrive sync for the Sims 4 folder to prevent file locks. If you use mods, update them after patches and run the New Save Test to identify if a mod or save file is causing the interaction query to hang.
Should I delete localthumbcache.package
Yes. If you use Mods or CC, deleting localthumbcache.package is one of the safest and most effective fixes for simulation hiccups and delayed interactions. The game rebuilds it on launch.
Why does OneDrive cause Sims 4 lag and freezing
The Sims 4 constantly writes saves, cache files, and thumbnails to Documents. If OneDrive syncs that folder, it can lock files during upload. When the game cannot write to a locked file, the simulation pauses and can appear as “lagging in simulation.”
Does DirectX 11 fix Sims 4 simulation lag
DirectX mode can improve rendering performance and stability on some systems, but simulation lag is primarily a logic bottleneck. If you have stuck Sims and clock stalls, focus on cloud sync conflicts, cache hygiene, save bloat, and mod stability first. Then benchmark DX11 vs DX9 for overall smoothness.
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