@puzzlezaddict
So, it's the base game lot Oakenstead in Willow Creek, a 50x50 lot. We've added a greenhouse and a lot of plants--one Sim is a gardener (PhD of Pollen). There are also some personal items, mostly paintings and some vet equipment, two rockets (one Sim is an Interstellar Smuggler), but I just played here rather than redecorated extensively, if you know what I mean. I took out all my mods and launched the game and was getting (I kid you not) 1.5 FPS. I disconnected from the Internet and that didn't help, and finally I said screw it and went to do something else.
(screenshot of the FPS last night, no mods, connected to Internet)
This morning, I came into the game intending to bulldoze the lot and not save after, in hopes of narrowing down the problem, and am getting 59.9 FPS!
(screenshot of the FPS this morning, modded, not connected to Internet)
I have a direct Ethernet connection, by the way. It's an Intel 9575LM Gigabit Network Connector. I don't have WiFi on this machine at all. It has 32 gig of RAM, SSDs, an older but still decent i-7 processor... I've attached my DxDiag.
Literally, all I did was disconnect from the Internet, close my game, sleep, reopen. Okay, I also had a PlantSim portal tree on the lot that I put in the household inventory, but that didn't seem to help.
And really, I don't think it's that my lot is overcluttered. Pics are too large to upload, but...
https://1drv.ms/u/s!AuaT-f7qP6bD-1cFLrVpG_wcNLdF?e=wxvCBf
https://1drv.ms/u/s!AuaT-f7qP6bD-1VuTVpXgpeDP933?e=qe6PJg
https://1drv.ms/u/s!AuaT-f7qP6bD-1bTEHeKyVXStSZk?e=prftuO
https://1drv.ms/u/s!AuaT-f7qP6bD-1gqJ7t1B9NZiFyC?e=Dos6Xr
Reading my DxDiag, I could probably stand to buy a bigger C drive, but I really think the issue here is Ethernet.
[Edit - Alas, it does slow down over time. Alas. I'm not only on a 50x50 lot, but I'm on a 50x50 "green" lot. I don't know if that makes a difference]
[Edit - Okay, as an experiment I turned off Eco Footprint gameplay and suddenly my framerate is fine. Okay, it also generated a last exception when I reloaded the lot. 😉 This is the only house where I'm having that problem, and I've also played the 64x64 lot in Brindleton Bay as a green lot with no issues. Oakenstead is 1-7 FPS with a green eco footprint and 50-60 FPS with Eco Footprint Gameplay turned off, and I continued to play and the FPS is fine, so I'm going to consider this fixed.]