Question Unity Editor + Builds suddenly running extremely poorly.

A few days ago, Unity, out of nowhere, started running like absolute crap. Before, my project ran at 140+ fps. Now, it's somewhere between 30 and 50 fps. It frustratingly stutters and chugs along, both in builds and in the editor (including the scene view). I have tried everything I could think of, but nothing seems to help. These are the things I've tried so far:

• Checked with the other developers on the project, to see if they were experiencing the same problems. They all said they had no issues at all.
  
• Reverted to a version of the project from before the moment the issue arose. Didn't work.
• Changed the renderer/API to Vulkan. It wasn't as choppy anymore (no more lag spikes), but there was extreme input latency. Unity also crashed a couple of times.
• Upon finding that changing the graphics API seemed to have an effect, I tried to play some other DX11 games. They all ran just fine. DX12 and Vulkan games were also fine. Doom Eternal runs at 90 fps at very high settings.
  
• Reinstalled the latest Geforce Experience drivers, just to be certain.
• Deleted my Unity install, and removed all Unity folders from my Temp folder, Appdata, Programdata etc. Removed the project. Ran a windows disk cleanup. Also did a 'find and fix errors'. Reinstalled Unity, redownloaded and reimported my project. Still the same.
• Tried playing a game that we released back in 2019, using our Steam build (launched it from Steam) and it was also choppy and slow all of the sudden.

Has anyone here had a problem like this before? I'm lost at sea. I can't even work on my game anymore.

 

From your description it doesn't sound Unity related, but instead something with your computer itself. I'd be looking at idle CPU usage (maybe some background process is churning away all your performance), GPU/CPU thermals and frequency under load (looking for abnormal thermal throttling), etc. Could be as simple as a heatsink clogged with dust you need to blow out.

 

Thanks Joe, but I don't thinks my computer is the problem, other games and productivity apps run great. Even with multiple games and programs open. Idle CPU usage is normal.

 

I have done some more tests and it turns out GPU usage goes to 100% in playback mode or when moving the camera in scene view. This makes no sense, as extremely heavy games run fine on my GPU (it's an rtx 2070). Does anyone have any ideas what this could mean?

 

What Unity version are you using? When I use Unity 2020.1.6f1 my scenes are normal (hundreds of FPS because they are almost empty, or even empty) but when I use Unity 2020.2.0b2 my scenes are stuck at 7-9 FPS, even if the scenes are empty.

 

Oh wow, really? Yeah that sounds a lot like the same problem I'm having. I'm using 2019.3.1f myself, I guess I'll try going back to a previous version of unity, see if that'll help. Thanks.