How to Demo FSR3 on Steam Deck (for free)

If you’re curious how FSR3 performs on Steam Deck (primarily the frame generation), there’s a way to demo it yourself for free.

Download the Immortals of Aveum demo on your Steam Deck
Launch the demo once
Navigate to the following folder on your Steam Deck

Home\.steam\steam\steamapps\compatdata\2555360\pfx\drive_c\users\steamuser\AppData\Local\P3\Saved\Config\Windows

Open the file called “Engine.ini”
Copy and paste the following at the bottom of it

[/Script/Engine.Engine]
bSmoothFrameRate=False

[SystemSettings]
D3D12.PSO.DiskCache=1
D3D12.PSO.DriverOptimizedDiskCache=1
gc.MinDesiredObjectsPerSubTask=20
gc.NumRetriesBeforeForcingGC=5
gc.TimeBetweenPurgingPendingKillObjects=300
niagara.CreateShadersOnLoad=1
r.AllowOcclusionQueries=1
r.CreateShadersOnLoad=1
r.GPUParticle.Simulate=1
r.GTSyncType=1
r.ShaderPipelineCache.BatchSize=50
r.ShaderPipelineCache.Enabled=1
r.ShaderPipelineCache.GameFileMaskEnabled=0
r.ShaderPipelineCache.LazyLoadShadersWhenPSOCacheIsPresent=1
r.ShaderPipelineCache.ReportPSO=1
r.ShaderPipelineCache.StartupMode=3
r.Shaders.Optimize=1
r.Tonemapper.GrainQuantization=0
r.Tonemapper.Sharpen=0.4
r.XGEShaderCompile.Mode=1
r.XGEShaderCompile.Xml.BatchGroupSize=256
r.XGEShaderCompile.Xml.BatchSize=16
r.XGEShaderCompile.Xml.JobTimeout=0.500000
r.XGEShaderCompile=1
s.ContinuouslyIncrementalGCWhileLevelsPendingPurge=0
s.ForceGCAfterLevelStreamedOut=0
r.AllowLandscapeShadows=0
r.AmbientOcclusionLevels=0
r.BloomQuality=0
r.DepthOfFieldQuality=0
r.LensFlareQuality=0
r.MipMapLODBias=3
r.MotionBlurQuality=0
r.ParticleLODBias=3
r.ReflectionEnvironment=0
r.RefractionQuality=0
r.SSR=0
r.SSS.Quality=0
r.SceneColorFringeQuality=0
r.Shadow.CSM.MaxCascades=1
r.Shadow.DistanceScale=0.001
r.Shadow.MaxResolution=2
r.ShadowQuality=0
r.SkeletalMeshLODBias=2
r.StaticMeshLODDistanceScale=0.4
r.ViewDistanceScale=0.4
r.VolumetricFog=0
 
[ConsoleVariables]
AllowAsyncRenderThreadUpdates=1
AllowAsyncRenderThreadUpdatesDuringGamethreadUpdates=1
AllowAsyncRenderThreadUpdatesEditor=1

This will severely downgrade the graphics because the Steam Deck can’t even hit 30 FPS in Immortals of Aveum by default.

Setup done. Open the “Immortals of Aveum” demo and mess around with the settings. FSR3 can be enabled under “display”, NOT graphics.

Believe it or not, I find FSR3 30 FPS to 60 FPS a totally playable experience. Feels much more responsive than I anticipated.