ue 4.26 Performance Issue on game - GPU profiling

Good afternoon all

See attached. Ever since updating to 4.26 by game runs like ■■■■. Over time the FPS degrades completely. Here are the basics of the setup:

  1. Small open world based on World Composition tools
  2. Does use global post-processing for a comic style look but as you can post-processing is not actually draining much effort

Based on the GPU profile the issue is with the Frame Render Finish, which when running in the editor uses very little GPU but when rendering in the game in real-time, uses up enormous amounts of GPU power and just gets worse over time. The game starts out at around 20fps and degrades to 5 fps over time.

Anyonw know what is causing this?

And here is the UE4 Stats File if anyone wants to deep dive (89 MB).

The problem is that the bottleneck moves around, so those stats aren’t all that useful. “Frame Render Finish” just means that your CPU can feed your GPU enough work that it’s fully occupied, whereas when that’s small, it means you’re instead bottlenecked on CPU (which is usually the case in editor.)

The best thing to do is to turn on/off individual features, and measure the frame rate difference, and see which features add the most cost that way. This will give you a much more precise measurement of what the challenge really is.

I have the same problem. Previously I had above 125 FPS in 4.21 under max setting . But after moving to 4.26.1 FPS is 60. There is no improvement in graphics that can be seen on PC displays. Very poor performance after removing legacy shaders for mobile devices.

I checked your stat file. Your GPU and render thread is getting stressed quite hard. You are drawing 31 million tris and almost 5k drawcalls. But it shouldn’t justify your drop your framerate to something like 5. However there is something going on in your render thread named CaptureCommand() which is taking 20ms. This seems to be bottlenecking your entire game.

I suggest trying to make a build a check the performance. I would never ever recommend testing performance in editor since it get progressivly worse every new UE version.

UE 4.26.2 New shader complexity count 1700 for mobile. UE 4.26.2 A new level of complexity for shaders is 1700 for mobile devices. Now it is impossible to use shader complexity tool.

I must admit another 10 fps loss in average on android. WTF?