Opening any BP in editor cuts frame rate from 1/3 to 1/2.

TheWolf · March 9, 2025, 12:46am

I’ve always assumed an FPS drop when opening a BP editor was normal, but for some reason recently it has become more pronounced. I’m seeing 1/4-1/3 drop when opening very simple BP’s to 1/2 drop opening more complex ones. Anim BPs are the worst offenders, some pushing to 3/4fps drop. Tried a number of solutions posted, but no dice.

Also, the size of the BP window has a big impact, fullscreen compared to a small window can equal a 10 fps difference - this is relative to the complexity of the BP. This symptom is monitor-agnostic.

I’m seeing most, if not all, of the tax added on the game thread.

Any tips greatly appreciated.

3-monitor array. 2x 4K / 1x 1440p
RTX 4090 (572.65)
Ryzen 9 3900x
UE installed on an M.2

sergio.gardeazabal · March 9, 2025, 1:24am

Hi, you can make a trace capture when the issue happens and open it with Unreal Insights.

That should throw a light on what system is adding the extra cost when a BP editor is open

TheWolf · March 9, 2025, 9:11pm

Thanks Sergio,

Although I’m an Insights neophyte, it appears the lion’s share of the added time is ‘Slate: Tick (Time and Widgets)’ Avg 8ms pre-opening BP, avg 30ms post. I’m not sure what to do with this information though, any tips greatly appreciated.

I can’t be 100% certain, but I believe it only reached this level after updating to 5.5.3.