EDIT: By request I tested Mirror's Edge and added the results below
As the title says, I bought a 3050 as a dedicated PhysX card in order to properly run some older titles that I still very much go back to from time to time. Here are the results in the 4 titles I tested, with screenshots where applicable:
Firstly, proof of the setup:
Imgur: GPUZ
Mafia II Classic results:
Benchmark run without the 3050 and max settings: 28.8 FPS
Benchmark run with the 3050 and max settings: 157.1 FPS
Screenshots: Imgur: Mafia II
Batman Arkham Asylum results:
Benchmark run without the 3050 and max settings: 61 FPS (but with MANY of the scenes in the low 30s and 40s)
Benchmark run with the 3050 and max settings: 390 FPS
Screenshots: Imgur: Arkham Asylum
Borderlands 2 results:
1 minute gameplay run in area with heavy PhysX without the 3050 and max settings: Could not enable PhysX at ALL. I tried everything including different legacy versions of PhysX and editing .ini files, all to no avail.
1 minute gameplay run in area with heavy PhysX with the 3050 and max settings: 122 FPS
No screenshots for this one since there isn't an in-game benchmark to screengrab, plus the test is very subjective because of that. But at the end of the day, only one setup is even allowing PhysX.
Assassin's Creed IV: Black Flag results:
Playthrough of intro without 3050 at max settings: 62 FPS (engine locked).
Playthrough of intro with the 3050 at max settings: also 62 FPS (engine locked).
It seemed PhysX wasn't dragging this title down when using the CPU for PhysX. I saw the effects working as pieces of the ship were splintering off into the air as it was being hit by cannon balls.
Mirror's Edge:
Breaking a few windows without the 3050: dipped to 12 FPS and stayed there for 49 seconds as the glass scattered
Breaking the same windows with the 3050: 171 FPS