Are you running any other programs when you play? You should close other programs and only play with Origin and Sims 4 running. The other programs could be interfering with TS4.
Do you have mods and CC installed in your game? If you do, they could be causing your game to lag. Especially if you have too many pieces of CC.
Also you can try reinstalling Origin as that seems to be hanging up many people when playing. Here are instructions on how.
- Make sure you are in Finder then click Go in the menu bar. Hold down Alt and the hidden Library folder will show up. Click on the Library folder.
- You now need to check in the following folders for any Origin files and folders:
Application Support (Origin)
Caches (Origin, com.ea.Origin)
Preferences (com.ea.Origin.plist)
Saved Application state (com.ea.Origin.savedState)
Open a Finder window and click on your Macintosh HD in the left hand section under Devices (if it's not there click on Finder in the menu bar then Preferences. Select the Sidebar tab and make sure Hard Disks is ticked under Devices), open Library, then delete the Origin folder.
After you've trashed them, empty the trash then restart your Mac. Then redownload and reinstall Origin.
Also try repairing your permissions. You can find this:
Open Disk Utility and Repair Permissions - Applications > Utilities > Disk Utility
Just trying to think of all the reasons it could be lagging.