I think I have found a bug on UE5 with chaos destruction. When I setup an object to be destructed, it works fine with no lag. When I setup my landscape, it works fine too. But when I put the destructable mesh on the landscape, it lags a lot. If I put the meshes on the default arena floor with the landscape under, it works fine again. So it seems to be lagging when the destructable meshes collide with the landscape.
I tried finding the reason of the lag, but I’m still kind of new to UE and profiling and such. From what I can tell, the lag isn’t actually because my CPU or GPU is at max power ( they actually go down from like 80% in the editor to like 5% in game ) and when I do a dumphitches, it dumps pretty much every frame saying the lag is from CPU Stall - Wait for Event. Seeing that + my GPU go down makes me feel like there’s a bug making the main thread wait/sleep for 80 ms or so every frame ? Like I said I don’t know much but that’s my guess.
I’m not sure if this can be replicated by anyone, but I made a video showing what is happening and some stats/dumps and posted it on the UE subreddit in case people knew, they didn’t and told me to post here. Here is the video if you want to see the issue: https://www.reddit.com/r/unrealengine/comments/plxemf/ue5_chaos_destruction_insane_lag_on_a_landscape/