This video gives a comparison of Dying Light: Definitive (or Platinum) Edition running on both the Switch OLED and Steam Deck OLED. Both the Switch version and the Steam Deck version are running from a microSD.
The Steam Deck version runs at a consistent 60 fps (versus the Switch's 30 fps average) and the recording is at 60. I attempted capping the frame limit to 90 fps, but in general the best it was getting up to was 67-70 fps with occasional bumps above, so I just capped it at 60.
I made a note in the video, but during a later portion of the gameplay on Switch (since I booted it up there first and could not remember where to go) I sped up the footage so that you would not have to watch me play like a game journalist for (what at least felt like) several minutes.
Steam Deck OLED graphics settings (other than default) are as follows:
Frame Limit (in Steam "..." menu, under the Battery settings) - 60 FPS (60 Hz)
Vertical Sync: On
Texture Quality: High
Shadow Map Size: Medium
Foliage Quality: Medium
Ambient Occlusion: Off
NVIDIA Depth of Field: Off
Motion Blur: Off
Antialiasing: On
Film Grain Effect: Off
Chromatic Abberation Effect: Off
