The Sims 3 - Can't fix lag!!

@FPSsweden  Yes, your specs are more than capable of running the game on high settings.  But there are other factors.  What world are you playing in?  Isla Paradiso is so poorly made that it will lag on any system, as the game engine gets overwhelmed trying to fix routing and other errors.  And are you running any other apps in the background?  Discord has been causing lag for players in other EA games recently, although I haven't heard anything about TS3 in particular.

Also, if you happen to have GeForce Experience, try disabling it to see if it helps.  It can cause problems when running alongside the game.  If you have a different game-enhancing app, you could try temporarily disabling it as well, although some of them (like MSI Afterburner) generally get along fine with TS3.

One quick way to narrow things down is to try playing while your computer is completely offline.  After you sign into Origin, put it in offline mode and then turn off wifi and/or pull the ethernet cable.  Test in Sunset Valley, Riverview, or Twinbrook; these are the most well-made EA worlds.  If things run smoothly, then this is an issue of the connection to EA servers, or something else that normally runs alongside the game.  (For example, Discord has been causing problems with other EA games lately.)

If you still get lag playing while completely offline, pull your entire TS3 game folder from Documents and try again.  Launching the game will spawn a clean folder, removing all possibly corrupt files at once.  If you have saves you want to keep, you can move them back later.

If you still get lag playing offline in one of the well-made worlds, even with a clean game folder in place, please run a dxdiag and attach the results to a post here.

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