Just to add -
@skfabby Just to note, this is confirmed on 5.4.4 as well. It seems pretty inconsistent. I’ve converted the same project from 5.3.2 to 5.4.4 three times now, and the threading issue appears in 2/3 occurrences. Game thread is running sequentially with RHIT instead of in parallel, causing ~35% performance loss for no good reason.
You can see a pretty insane (25.8ms!) frame time here. 8ms is spent waiting for RHI. This is the same test scene that was running at 17.5ms in the screenshots above.
Other comments on CPU performance in UE5
This is a new CPU thread process that I haven’t seen consuming time on 5.3.2 which appeared in 5.4. Basically 2.8ms of CPU time (that’s a lot!!!) is being spent on landscape grassmap “getActionalableUpdate.”
Secondly:
Slate in 5.3.2 consumed a lot of CPU time on the Game Thread, I believe to run the editor windows. When run in full-screen, this goes away because Slate is not being drawn. HOWEVER, in 5.4.4, this is very unreliable and quite often Slate continues to eat up 2-3ms of CPU time even when the game is played in fullscreen PIE or Standalone.
This can give the impression of poor game performance but is caused by the editor spending a lot of CPU cycles on slate unnecessarily. It’s not clear what causes this. in 5.4.4 sometimes it happens, sometimes it doesn’t. It happens more frequently than it doesn’t, though, and the result is a much worse FPS/longer Frame time.