Frame Generation - Switching between FSR 4 and DLSS 4.5

Development Rendering
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1

Hey friends!

I was trying to install both DLSS 4.5 and FSR 4 into UE 5.8. Individually they work fine, but once both of them are in the project, I can’t change my frame generation mode as one of the plugins hijacks the swapchain right away.

AMD’s documentation states: Using the D3D12 Async. Present (r.FidelityFX.FI.OverrideSwapChainDX12) option is incompatible with other frame interpolation technologies. Only one may be enabled at one time and toggling between them requires a restart of the title.

My question is, how do I go about changing between them after the game restart? I made the user-side logics and everything, but on game restart what exactly do I do to disable DLSSG and enable FSR frame gen? It seems to stay with DLSS no matter what.

I tried building a custom function to enable/disable them via writing cvars to Engine.ini, as per other discussions I found, but it doesn’t swap the frame generators, even though looks ok on paper.

Any help would be greatly appreciated!

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you cant have both FG plugins claim the swapchain at once, that part of AMD docs is correct.

do the toggle before either plugin inits: on game launch read user preference from GameUserSettings ini before engine plugins load, write r.NGX.DLSSG.Enable 0/1 and r.FidelityFX.FI.Enabled 0/1 via FConfigCacheIni, then restart. at runtime to swap, set both off, SaveSettings, call RequestExitWithStatus and relaunch — live toggle will stay stuck to first claimant.

in DefaultEngine.ini put both cvars as 0 by default and let your boot code enable exactly one.