Sims 3 running slower on my new computer? WTH!

Not entirely sure I qualify as "lovely," but let's see what we can do. :)

You already had a response to a similar but less detailed question over here.
https://forums.thesims.com/en_US/discussion/comment/16774841/#Comment_16774841

The first thing to address as @puzzlezaddict indicated, much more important than anything else, would be the frame rates you are getting on your GTX 1060. TS3 has no functional built-in fps limiter and that card is powerful enough to run wild on it. The frame rates in excess of what your monitor can possibly interpret are the equivalent of digital noise and can lead to graphics glitches, performance issues, screen tears, crashes, and can even damage the card over time.

Have you set up the Nividia Control Panel to force vertical sync on this card for TS3 as the illustrations she provided shows? If playing in windowed mode is required or if the Control Panel doesn't lock things in, which it does not always do, then we move on to Nvidia Inspector again as shown (download required) and explicitly enter the Frame Rate Limit there. To see what kind of fps rates you are actually getting in-game, ctrl+shift+C to bring up the cheats console, type fps on (enter). As you play and move the game camera around, the displayed frame rates should never go above the refresh rate of your monitor. Most are 60 Hz, so 60 fps is the goal for the upper limit, some monitors can run higher. To make the display go away, cheats console again and fps off (enter).

If this is a laptop then you may have dual graphics. Desktops off the shelf don't usually have these. But in that case on the correct profile in the Nvidia Control Panel for TS3.exe (Patch 1.69) or TS3w.exe (with the "w" for Patch 1.67) there should be an option to Use the Higher Performance Card to ensure that any Intel or other integrated chip is not being used for graphics instead.

If things are staying locked in at or under 60 fps and you are still having these performance issues, then we can start to look for other causes.

"igazor;c-16776806" wrote:
Not entirely sure I qualify as "lovely," but let's see what we can do. :)

You already had a response to a similar but less detailed question over here.
https://forums.thesims.com/en_US/discussion/comment/16774841/#Comment_16774841

The first thing to address as @puzzlezaddict indicated, much more important than anything else, would be the frame rates you are getting on your GTX 1060. TS3 has no functional built-in fps limiter and that card is powerful enough to run wild on it. The frame rates in excess of what your monitor can possibly interpret are the equivalent of digital noise and can lead to graphics glitches, performance issues, screen tears, crashes, and can even damage the card over time.

Have you set up the Nividia Control Panel to force vertical sync on this card for TS3 as the illustrations she provided shows? If playing in windowed mode is required or if the Control Panel doesn't lock things in, which it does not always do, then we move on to Nvidia Inspector again as shown (download required) and explicitly enter the Frame Rate Limit there. To see what kind of fps rates you are actually getting in-game, ctrl+shift+C to bring up the cheats console, type fps on (enter). As you play and move the game camera around, the displayed frame rates should never go above the refresh rate of your monitor. Most are 60 Hz, so 60 fps is the goal for the upper limit, some monitors can run higher. To make the display go away, cheats console again and fps off (enter).

If this is a laptop then you may have dual graphics. Desktops off the shelf don't usually have these. But in that case on the correct profile in the Nvidia Control Panel for TS3.exe (Patch 1.69) or TS3w.exe (with the "w" for Patch 1.67) there should be an option to Use the Higher Performance Card to ensure that any Intel or other integrated chip is not being used for graphics instead.

If things are staying locked in at or under 60 fps and you are still having these performance issues, then we can start to look for other causes.

So it turns out what really was affecting my computer were corrupted cc. Not sure how I ended up with them since I did some cleaning before transferring.

But anyhow, I can't seem to keep my game at 60fps on windowed mode. I tried the aforementioned tips about limiting the fps, and while it stays locked in fullscreen mode, I'm struggling in keeping it in 60fps window mode

Have you added Nvidia Inspector to the mix and explicitly yourself entered the Frame Rate Limit of 60 or some value right around there? The Nvidia Control Panel alone won't work in windowed mode, but coupling it with Inspector should. And have you since rebooted your computer, sometimes it does take that for things to lock in.

Nvidia Inspector gives me the options of 20-40 FPS. I cannot manually set it to 60fps

Okay, you caught me. I don't use Inspector because I don't even have an Nvidia card, mine is AMD so I have to use different tools to accomplish this. But I think you might have an older version of Inspector there than your card and OS might require.
https://www.guru3d.com/files-details/nvidia-profile-inspector-download.html

Also what exactly are you using for a screen/monitor and what is its refresh rate?

@SimplyJen, what do you see as getting in the way here?

Could be the older version of Inspector here... Just to be safe, I usually link to Nvidia website instead of GeForce Experience. After a driver check and w/ the version of NVIDIA Profile Inspector I linked, see if you can now set it to your monitors refresh rate.

If none of that works, it doesn't hurt to do a clean driver install.