FPS Drop

@leckenby-kate  You could try the graphics overhaul offered by Sim4Sims.  (Google should find it for you.)  This isn't a mod but rather a set of graphics settings designed to make the game run more smoothly.  For example, it changes LOD values so the game doesn't constantly need to switch between high and low level-of-detail images.

Given your hardware, you definitely don't need the "performance" version, which is for systems that can't handle the highest graphics settings.  If you don't like it, uninstalling is as simple as removing the file.

@JeanVW  I haven't heard anything about this override helping with the low fps in Build/Buy specifically, but your system can certainly handle the higher settings, so it might be worth trying.  At worst, it doesn't help and you delete the file.

Which one would I chose  for smoother gameplay?

Do I go with the Performance version Or the Top one that just says SGR file?

According to @puzzlezaddict , you don't need the Performance version, so you can just download the regular SGR one. There is one with the DOF and one without the DOF (Depth of Focus), which is the blurry thing in the background. It's all up to preference.

@leckenby-kate  Yes, as JeanVW mentioned, you can choose the regular one.  Feel free to experiment with different copies though.  As long as you're only using one at a time, you'll be fine.

So do I just put the downloaed file in the ConifigOverride folder?

@leckenby-kate  Yes, that's all you need to do, and if you don't like it, remove the file from ConfigOverride and you're done.