UE5.3 IS 14% SLOWER THAN UE5.1!!!
I’ll keep this short and concise to respect your time. I unwisely upgraded my project from UE5.1 to UE5.3 a couple months ago so I could use certain 5.3 compatible Fab assets. This was the dumbest mistake I’ve made in the 3 years of developing my game. On my particular hardware (RTX 4080, 12th gen intel i5-12600k, 64gb RAM) I get precisely a 14% performance drop no matter WHAT I do. This is devastating for me, because my game is set in ultra realistic forests with dense foliage.
I’ve scoured forums for explanations on why 5.3 may run slower than 5.1, but the only conclusions I’ve come to ARE:
-There’s a bug in the 5.1 editor that forces the screen percentage to the minimum, giving the illusion of great performance. This helps, but even after correcting the screen percentage bug there’s still a huge performance difference
-Apparently 5.3 has changes to the way GI is handled, so the engine is simply worse and with
greater over head of extraneous features, and it is what it is
I’m making one of my first forum posts now to desperately attempt to gather any other tweaks I can make to speed up 5.3 so its a little closer to 5.1, any and all interesting knowledge from you all would be much appreciated.
(Side note: I even tried downgrading my project engine version using the experimental “Downgrader” Fab plugin, but its very glitchy and seems very unwise to move forward finishing development on with sketchy downgraded assets and no way to go back.)
Comparing 5.1 to 5.3:
Important Note: On both games im running ‘r.ScreenPercentage 100’ because in the packaged 5.3 game, the default screen percentage is 50%. The reason I know this command is working successfully to force percentage is because both games FPS reflects accordingly to what you’d expect.
Fresh Project, third person template:
5.1 Third person template:
Peak FPS:
160fps - 100% screen resolution
5.3 third person template:
140fps - 100% screen resolution
Dense foliage levels:
5.1 Dense Foliage:
76fps - 100% screen resolution
5.3 Dense Foliage:
67fps - 100% screen resolution
The real sucker punch is 5.3 also looks worse too! I’m not sure why its so much brighter with the same sky light and post process settings.
Identical scene details:
-All perf tests done in packaged development build
-Dynamic skylight
-Dynamic Directional light with matching details: 40,000 Dynamic shadow distance, 51,200 distance field shadows, 4 cascading shadows, matching indirect lighting, etc.
-manual post process volume
-No exponential height fog
-exactly 60 thousand foliage instances on each level
Identical project settings in both engines:
-Nanite disabled and forced false with console command: ‘nanite 0’
-DX12
-Anti aliasing: TSR
-software ray tracing mode: global tracing
-shadow map method: virtual shadow maps
-MSAA count: 4x MSAA