I’m playing on Steam, with Nvidia RTX 3080 GPU, Intel i9 CPU, 32G RAM.
I was getting insane lag spikes every minute. Finally I found the solution:
Settings->System->Display->Graphics->Advanced graphics settings->TURN OFF Hardware-accelerated GPU Scheduling!
Now I get 0 lag spikes. Previously I’ve tried everything, lowering graphics settings, lowering thread count, CPU and GPU thermal throttling, network issues, nothing worked until this fix.
Hopes this helps others with the same issue!