Updated from 4.7 to 4.8.2 -> massive performance issues

Development Platform & Builds Debugging, Optimization, & Profiling
, , , ,
1

Hello,

I just updated from UE 4.7 to 4.8.2 and now I have massiv performance problems. Maps that run with konstant 120FPS in 4.7 now run with 20-30 FPS.

What is the problem? Is it a bug with the new version or is there some tweak or ‘hidden’ option that is causing this problem?

CPU: Intel Xeon E3-1231 v3
GPU: Sapphire Radeon R9 290 Tri-X OC (4GB)
RAM: 16 GB
OS: Win7 (64Bit)

This is a Blueprint light:

LightBP.PNG.jpg
LightBP.PNG.jpg1604×727 130 KB

This is a default pointlight set to movable:

50289-pointlight.png
50289-pointlight.png676×901 578 KB

[Both force this problem click][3]

50290-gpu_1.png
50290-gpu_1.png1919×899 66.8 KB

50301-gpu_2.png
50301-gpu_2.png1919×965 78.9 KB

50302-gpu_3.png
50302-gpu_3.png1919×765 48.6 KB

Thank you!

2

Including link back to your forum post regarding this issue: [Bug Report] Massive performance issues in UE4.8.1 (incl. documentation) - Feedback for Unreal Engine team - Unreal Engine Forums

Thanks for providing the information, we will continue this investigation here on the AnswerHub.

3

I noticed that if is disable cast shadow from the light the FPS are back at 120.
So there must be a problem with casting shadows…

4

Hi KAEPS133 -

We have been attempting to reproduce this performance lost internally since your original forums report and have not been successful as of yet. If it is possible can you share a sample project demonstrating the same performance lost for us to test?

IF you need to keep it private your can place it in a dropbox or Google Drive and link it to me via the Forums Private Message System.

Thank You -

Eric Ketchum

5

I also have been having this issue, reloading the map usually jumps it back up, reimporting is a lot slower (Was a second or two before if that, is now 20 seconds or more for the smallest of assets)… What happened in that hotfix? D:

6

Hello -

I spent sometime today running an additional set of test for this particular issue. I will layout the exact results below, but I am not able to reproduce this issue in a blank project with a Blueprinted Light Source. I will attach the test projects below for 4.7.6, 4.8.3 and 4.9P1. If you can reproduce the increase in Light Rendering Time in one of these projects please feel free to comment and reopen this issue. If you are only able to reproduce this in a personal project then it is most likely an optimization issue for your project and I can still offer some guidance but please open a new Answerhub post in Rendering for assistance with that issue.

Thank You

Eric Ketchum

RESULTS:
4.7.6 (Base Line - assumed to be correct per question)

0.62ms In Editor

  • 0.13ms Shadow Depths to Opaque
  • 0.32ms Shadow Projection to Opaque
  • 0.15ms Standard Deferred

0.67ms New Editor Window

  • 0.13ms Shadow Depths to Opaque
  • 0.35ms Shadow Projection to Opaque
  • 0.17ms Standard Deferred

1.36ms Standalone Game

  • 0.33 Shadow Depths to Opaque
  • 0.54 Shadow Projection to Opaque
  • 0.46 Standard Deferred

4.8.3 (Converted Project from the 4.7.6 version)

0.59ms In Editor

  • 0.15ms Shadow Depths to Opaque
  • 0.36ms Shadow Projection to Opaque
  • 0.14ms Standard Deferred

0.67ms New Editor Window

  • 0.13ms Shadow Depths to Opaque
  • 0.36ms Shadow Projection to Opaque
  • 0.17ms Standard Deferred

1.29ms Standalone Game

  • 0.33 Shadow Depths to Opaque
  • 0.52 Shadow Projection to Opaque
  • 0.40 Standard Deferred

4.9.0 Preview 1 (Converted directly from 4.7.6 version)

0.51ms In Editor

  • 0.14ms Shadow Depths to Opaque
  • 0.25ms Shadow Projection to Opaque
  • 0.11ms Standard Deferred

0.30ms New Editor Window

  • 0.13ms Shadow Depths to Opaque
  • 0.11ms Shadow Projection to Opaque
  • 0.05ms Standard Deferred

0.99ms Standalone Game

  • 0.19 Shadow Depths to Opaque
  • 0.49 Shadow Projection to Opaque
  • 0.29 Standard Deferred

Test_Project - 4.7.6
Test_Project - 4.8.3
Test_Project - 4.9.0 Preview 1

7

Played a bit with the 4.9.0 P1 and this ‘fixes’ the problem with the light in some way. The FPS only drop now to ~90 and it’s playable but I don’t think that 1 light source should cause a 30 FPS drop. But even with 5 or 10 Lights the FPS stay on 90 so thats a good thing.

In 4.8.3 I still have the problems. Both tested on Windows 10 with my Project.

8

Hi KAEPS133 -

We are in the process of installing a Windows 10 Machine for our team to test on and once that process is complete I will re-run my tests and post the results here. In the meantime, if you were using Windows 10 when originally reporting this issue, I would get the latest NVidia driver which was released the day after Windows 10 and has known fixes for Windows 10 based rendering.

Thank You

Eric Ketchum