Excessive load times, simulation lag rendering game unplayable

@kspringy  Did you try playing in a new Sims 4 user folder with absolutely nothing added back?  If not, please do so now and let me know what happens.

If that doesn't or didn't help, please run a dxdiag and attach it to a post.

https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/

Please also let me know whether OneDrive is running on this computer, and if so, how much free storage it has.  I'm not suggesting you buy more, only saying it's worth checking.

I'm having the exact same issue. The game has always run smooth for me until a couple of weeks ago. The lag is unbearable! It takes my game 5 minutes to save and several minutes of sitting through loading screens just to go to another lot. There's so much input lag. Every interaction takes several moments to pop up. Also, distant Sims aren't rendering in properly. I have to zoom in to them and wait a couple of seconds for them to look normal. I've repaired my game files, but it doesn't seem to help.

I've posted my dxdiag hoping someone can see if maybe my computer is actually causing this to happen.

@NightlyCoffee  Are you running GPU Tweak or anything else from Asus?  I ask because your dxdiag lists a number of errors from what is apparently a component of Asus software, including GPU Tweak.  Please shut down any of these programs you have installed, by which I mean either uninstall them or kill them in the Task Manager and make sure they don't restart.  (Check the background processes list too.)  If your main save is still affected, please test in a new one.

If you see the same problem in a new save, please try playing in a clean boot:

https://support.microsoft.com/en-us/topic/how-to-perform-a-clean-boot-in-windows-da2f9573-6eec-00ad-2f8a-a97a1807f3dd

The one service to leave enabled is the EABackgroundService, which the EA App needs in order to run.  Disable the rest as described.

When you reboot your computer, go through the Task Manager's background processes list shutting down any service that doesn't absolutely need to be running, for example anything from MSI Afterburner to RGB software might still be enabled.  If you accidentally kill a critical process and it doesn't restart on its own, just reboot your computer again.

Don't open anything other than Sims 4 and the EA App while testing, not even a browser window.

Thank you so much for responding.

I'm not very tech savvy, so unfortunately I'm unaware if my computer is running GPU Tweak and Asus. My husband set this computer up for me. I did try to uninstall those files, but I couldn't find them in the uninstall programs list. I did, however, follow your instructions and did a clean boot only having EA Background Service running. It didn't make a difference in my main save or a brand new save. Everything was still unbearably laggy and choppy.

I decided to install the EA App and TS4 on my husband's computer and I transfered my saves/tray/mods/user settings to his computer. The game ran smooth like butter including my current save file. I played it for over an hour on his computer and had zero issues. Definitely something on my computer causing issues with the game.

I'll have my husband look at my computer and see if he can remove the Asus stuff causing issues. I'll also try uninstalling TS4 on my computer and install it fresh and see if that helps.

@NightlyCoffee  Another thing you can try is playing Sims 4 while your computer is offline.  You can sign into the EA App and put it in offline mode, then disable wifi and/or disconnect the ethernet cable.  Even if you'd never play like this in general, it's a useful diagnostic test.

Let me know what you and your husband find, and we'll go from there.